What is the maximum transmission distance of the LS-SM551G-40I module?

It supports stable optical data transmissions up to 40km over single-mode fiber links.

Does this SFP transceiver support real-time diagnostic monitoring?

Yes, it features integrated Digital Optical Monitoring (DOM) compliant with SFF-8472 standards.

What type of optical connector does this module utilize?

The module is equipped with a standard duplex LC/UPC fiber interface.

Can this transceiver operate in extreme outdoor temperature conditions?

Yes, its industrial-grade design guarantees reliable operation from -40°C to 85°C.

We're doing a huge deployment and need like 200 of these. Any bulk pricing for enterprise buyers?

For sure! We offer tiered B2B discounts. For 200 pieces, the unit price drops nicely. Just ping our sales team and we’ll sort out a custom quote for your procurement.

Do these support DDM? My sysadmins want to pull real-time RX/TX levels via SNMP.

Yes, they feature built-in DOM/DDM following the SFF-8472 standard. Your NOC team can easily monitor temperature, voltage, laser bias, and TX/RX optical power in real time.

Just to be 100% sure, what kind of fiber patch cables do I need for this?

You'll need Single Mode Fiber (SMF) patch cables with a Duplex LC connector. This module is optimized specifically for that setup to hit the full 40km reach using a 1550nm wavelength.

Hey, are these compatible with Cisco Catalyst and Ubiquiti switches? Need to mix them in our rack.

Yes! This module is fully MSA compliant, so it plays nice with Cisco, Ubiquiti, MikroTik, and other major brands without triggering any OEM lock-out errors.

Breadcrumb: Home; Products; Optics Transceivers | SFP Modules; 1/2/4G Transceiver Modules; 1G SFP; 201973

Click to open expanded view

LINK-PP LS-SM551G-40I 1.25G SFP 1550nm 40km Duplex LC DOM SMF Optical Transceiver Module (Industrial)

Name: LINK-PP LS-SM551G-40I 1.25G SFP 1550nm 40km Duplex LC DOM SMF Optical Transceiver Module (Industrial)
Brand: LINK-PP
SKU: 201973
Price: 10.75 USD
Availability: InStock
Rating: 5 (48 reviews)

# 201973

Product: LINK-PP LS-SM551G-40I 1.25G SFP 1550nm 40km Duplex LC DOM SMF Optical Transceiver Module (Industrial)
SKU: 201973
P/N: LS-SM551G-40I
Price: $ 12.5
Stock: 121 in Stock
Sold: 1.9K
Product URL: https://www.l-p.com/products/491457.htm

For Order Over $1000 Get $15.00 Off , Code: Linkpp15

For Order Over $3000 Get $50.00 Off , Code: Linkpp50

For Order Over $5000 Get $100.00 Off , Code: Linkpp100

New Users: $10 Coupon for Orders , Code: linkpp2610

48 Reviews

4 Questions

Request Stock

1.9K Sold

$ 12.5

Free shipping over $600, If you need a more favorable price, please contact us directly.

Qty (pcs) :

Unit Price :

$ 12.5

100

$ 11.875

1000

$ 11.5

3000

$ 11.125

6000

$ 10.75

Manufacture: LINK-PP

P/N: LS-SM551G-40I

Compatible:: LINK-PP; FS

Compatible P/N:: LS-SM311G-02C | 2km; LS-SM311G-02I | 2km; LS-SM311G-10C | 10km; LS-SM311G-10I | 10km; LS-SM311G-20C | 20km; LS-SM311G-20I | 20km; LS-SM311G-40AI | 40km; LS-SM311G-40C | 40km; LS-SM311G-40I | 40km; LS-SM551G-40C | 40km; LS-SM551G-40I | 40km; LS-SM551G-60C | 60km; LS-SM551G-60I | 60km; LS-SM551G-80C | 80km; LS-SM551G-80I | 80km; LS-SM551G-A0C | 100km; LS-SM551G-A0I | 100km; LS-SM551G-A2C | 120km; LS-SM551G-A2I | 120km; LS-SM551G-A6C | 160km; LS-SM551G-A6I | 160km

Shipping:

To Be Negotiated

Free Shipping

Can't deliver

to United States via {{now_chooseship?now_chooseship.name:''}}

Estimated delivery time : {{now_chooseship?now_chooseship.datemin:''}}-{{now_chooseship?now_chooseship.datemax:''}} days. See details

5-Year Warranty 30-Day Returns 30-Day Exchange

Stock:

{{parseInt(detail_data.left_num) ? detail_data.left_num +' in Stock' :detail_data.zeroStockOrder==0?'Out of Stock':'Available'}} .

Quantity:

( Min. Order {{detail_data.prodInfo.minimum_ordered_quantity}} )

undeliverable

Total Price:

{{ detail_data.displayed_price.unit_prefix }} {{ detail_data.displayed_price.original_total_price }} ( {{ detail_data.displayed_price.rate_of_discount }}% OFF ) {{detail_data.displayed_price.ex_sell_type}}

Add to wish

Specifications

Specification
Videos
Matching Products
Download
Q&A
Customer Reviews

LINK-PP LS-SM551G-40I 1.25G SFP Specifications

The LINK-PP LS-SM551G-40I is an industrial-grade 1.25G SFP transceiver module engineered for high-performance optical networking. Operating over a 1550nm wavelength, it supports transmission distances up to 40km via duplex LC single-mode fiber. This robust optical transceiver complies with MSA and SFF-8472 standards, providing exceptional data integrity under demanding industrial environments ranging from -40°C to 85°C.

LINK-PP Part Number	LS-SM551G-40I	Vendor Name	LINK-PP
Form Factor	SFP	Max Data Rate	1.25Gbps
Wavelength	1550nm	Max Cable Distance	40km
Connector	Duplex LC	Media	SMF
Transmitter Type	DFB	Receiver Type	PIN
TX Power	-5 to 0dBm	RX Power	-23 to -1dBm
Receiver Sensitivity	-23dBm	DOM Support	Yes
Operating Temperature Range	-40 to 85°C	Protocols	SFF-8472 MSA Compliant, IEEE 802.3ah-2004

Videos

Matching Products

Pictures

ID#

Description

Price

Stock

Add to Cart

Download

Product Drawing

PDF
LS-SM551G-40I.pdf

Questions & Answers
Ask a Question

No data

Q: We're doing a huge deployment and need like 200 of these. Any bulk pricing for enterprise buyers? By A***n on 2026-05-07

A: For sure! We offer tiered B2B discounts. For 200 pieces, the unit price drops nicely. Just ping our sales team and we’ll sort out a custom quote for your procurement. By admin on 2026-05-07
Q: Do these support DDM? My sysadmins want to pull real-time RX/TX levels via SNMP. By D***n on 2026-01-12

A: Yes, they feature built-in DOM/DDM following the SFF-8472 standard. Your NOC team can easily monitor temperature, voltage, laser bias, and TX/RX optical power in real time. By admin on 2026-01-12
Q: Just to be 100% sure, what kind of fiber patch cables do I need for this? By L***z on 2025-09-18

A: You'll need Single Mode Fiber (SMF) patch cables with a Duplex LC connector. This module is optimized specifically for that setup to hit the full 40km reach using a 1550nm wavelength. By admin on 2025-09-18
Q: Hey, are these compatible with Cisco Catalyst and Ubiquiti switches? Need to mix them in our rack. By S***s on 2025-05-06

A: Yes! This module is fully MSA compliant, so it plays nice with Cisco, Ubiquiti, MikroTik, and other major brands without triggering any OEM lock-out errors. By admin on 2025-05-06

Customer Reviews
Write a Review

{{stardata.star}}

{{comment.count}} reviews
5 Stars

{{comment.star5}}%

4 Stars

{{comment.star4}}%

3 Stars

{{comment.star3}}%

2 Stars

{{comment.star2}}%

1 Star

{{comment.star1}}%

All Reviews ({{comment.star_num?comment.star_num:comment.count}})

All Reviews

5 stars only

4 stars only

3 stars only

2 stars only

1 star only
Reviews with Pictures ( {{comment.pic_comment}} )
See All Reviews

No data

T***n

Peru

Verified Purchase

5 .0

2026-04-27

Great build quality on this industrial grade SFP 40km. DDM stats are very accurate.

183 Helpful vote Comments

S***s

Bolivia

Verified Purchase

5 .0

2026-03-21

DDM feature is super handy for troubleshooting.

77 Helpful vote Comments

S***g

Ukraine

Verified Purchase

5 .0

2026-02-22

Reliable gigabit link for our campus network.

162 Helpful vote Comments

P***s

Argentina

Verified Purchase

5 .0

2025-12-25

Solid duplex LC SMF optics for our enterprise network upgrade. Will buy more!

140 Helpful vote Comments

J***g

Macao

Verified Purchase

5 .0

2025-11-16

Unbeatable price for 40km SMF optics!

132 Helpful vote Comments

J***n

Russian Federation

Verified Purchase

5 .0

2025-11-12

Temps stay low, great industrial SFP. ❄️

183 Helpful vote Comments

M***o

Finland

Verified Purchase

5 .0

2025-10-22

top , Fast shipping , works perfectly

69 Helpful vote Comments

L***n

Portugal

Verified Purchase

5 .0

2025-09-26

Works flawlessly over 40km single mode fiber.

56 Helpful vote Comments

D***h

Italy

Verified Purchase

5 .0

2025-09-21

Perfect 1G SFP module for fiber backhaul!

157 Helpful vote Comments

V***l

Denmark

Verified Purchase

5 .0

2025-09-04

No need to pay for a branded Optical Transceiver Module when these work flawlessly for a fraction of the cost.

45 Helpful vote Comments

J***r

Macao

Verified Purchase

5 .0

2025-07-27

Good MSA compliant 1G SFP optics. Recognized immediately by my MikroTik CRS switch.

66 Helpful vote Comments

R***z

Peru

Verified Purchase

5 .0

2025-07-27

Cheaper than OEM, but this 40km industrial transceiver holds link perfectly without packet drop.

54 Helpful vote Comments

M***h

Poland

Verified Purchase

5 .0

2025-07-21

Fully MSA compliant, detected right away.

94 Helpful vote Comments

J***e

Mexico

Verified Purchase

5 .0

2025-07-19

I’m so happy with everything about this purchase. It was Fast delivery and a great product.Will definitely shop again

107 Helpful vote Comments

I***o

Spain

Verified Purchase

5 .0

2025-05-16

Worked great and reduced bottleneck. Haven't had any issues whatsoever with these Optical Transceiver Module. Good material quality and feel. So I bought the second one as a spare.

41 Helpful vote Comments

J***k

South Africa

Verified Purchase

5 .0

2025-05-16

Replaced dying optics with this MSA compliant 1G SFP. Works instantly across multiple brands without OEM lockouts. Built-in DOM tracks laser bias accurately during our heavy loads.

77 Helpful vote Comments

D***n

Norway

Verified Purchase

5 .0

2025-04-02

Rock solid 1550nm DFB laser performance. ⚡

76 Helpful vote Comments

S***u

Turkey

Verified Purchase

5 .0

2025-03-22

Thanks for your wonderful service!Will come back again soon.

10 Helpful vote Comments

M***z

Portugal

Verified Purchase

5 .0

2025-03-21

Awesome industrial transceiver for harsh outdoor setups.

134 Helpful vote Comments

J***r

France

Verified Purchase

5 .0

2025-03-08

Purchased 30 pcs 5 months ago and working without any problem until now.

119 Helpful vote Comments

W***r

Dominican Republic

Verified Purchase

5 .0

2025-02-23

Plug and play 1.25G SFP 1550nm. The DOM feature helps my monitoring dashboard greatly.

126 Helpful vote Comments

M***t

Dominican Republic

Verified Purchase

5 .0

2025-02-03

Deployed these 40km industrial transceivers in our outdoor cabinets. Temp drops to -20C here, but DDM shows stable TX/RX levels. Flawless compatibility with our edge switches!

108 Helpful vote Comments

A***r

Poland

Verified Purchase

5 .0

2025-01-26

Tested the duplex LC SMF module on a 35km campus fiber run. The 1550nm DFB laser pushes great signal, RX sensitivity is well within -23dBm specs. Recommend for ISPs!

73 Helpful vote Comments

A***r

United States

Verified Purchase

5 .0

2025-01-22

product, good price, the tech , customer service very profession

17 Helpful vote Comments

B***z

Ukraine

Verified Purchase

5 .0

2025-01-21

Using these for an outdoor IP camera network. Wide temp range is exactly what's needed.

50 Helpful vote Comments

J***e

Argentina

Verified Purchase

5 .0

2025-01-12

I am very pleased with my experience with Link-pp! The shipping was very Fast, Would recommend this store! Keep up the great work...

65 Helpful vote Comments

L***u

Bulgaria

Verified Purchase

5 .0

2025-01-09

I was very happy with the quality of the Optical Transceiver Module.

75 Helpful vote Comments

D***n

Brazil

Verified Purchase

5 .0

2025-01-03

Fast shipping for our lab. The 1550nm wavelength penetrates long fiber runs beautifully.

57 Helpful vote Comments

P***z

France

Verified Purchase

4 .0

2024-12-25

FedEx delayed my batch of industrial grade SFP 40km modules, though performance is solid.

113 Helpful vote Comments

A***r

Spain

Verified Purchase

5 .0

2024-12-16

Great service,great prices,Fast shipping, I will be buying a lot of things from them thanks

147 Helpful vote Comments

C***l

Malaysia

Verified Purchase

5 .0

2024-12-15

The products are amazing for the price and I have been very satisfied with my dealing with them.

71 Helpful vote Comments

E***z

Peru

Verified Purchase

5 .0

2024-11-15

Setting up a remote base station backhaul. The industrial temperature -40 to 85°C rating is a lifesaver. Link came right up at 1.25Gbps over single mode fiber.

107 Helpful vote Comments

E***p

Philippines

Verified Purchase

5 .0

2024-10-13

Items arrived on time.Very good.

39 Helpful vote Comments

N***p

Israel

Verified Purchase

5 .0

2024-07-18

The item ordered arrived ahead of actual expected delivery date and work smoothly.

63 Helpful vote Comments

C***y

United Kingdom

Verified Purchase

5 .0

2024-07-08

Order 400G Transceiver Modules from them all the time.Will continue using it in the future.

66 Helpful vote Comments

S***g

Indonesia

Verified Purchase

5 .0

2024-06-25

Website easy to use and stock was delivered quickly.

42 Helpful vote Comments

R***n

Mexico

Verified Purchase

5 .0

2024-03-24

Placed the order easily, Fast shipping. Thanks Yoeng, keep me posted the order status till to my desk, good job. So far all good – I have heard nothing from my lab which is a good sign!

110 Helpful vote Comments

A***n

Japan

Verified Purchase

5 .0

2024-03-02

It was really easy to navigate and place the order.I have ordered for years from them and always have a great experience, time after time! I will continue ordering for the rest of our lives!!!

68 Helpful vote Comments

A***s

Philippines

Verified Purchase

5 .0

2023-12-07

Works as described. Happy with the purchase

147 Helpful vote Comments

S***s

United States

Verified Purchase

5 .0