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Pre-Term Fiber Assemblies
MTP Trunk Assemblies
MTP Fanout Cables
MTP Cassettes
Fiber Optic Enclosures
Fiber Optic Patch Cables
Ethernet Patch Cables
Ethernet Cable Bundles
Unterminated Fiber By The Foot
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Pre-Term Fiber Assemblies
MTP Trunk Assemblies
MTP Fanout Cables
MTP Cassettes
Fiber Optic Enclosures
Fiber Optic Patch Cables
Ethernet Patch Cables
Ethernet Cable Bundles
Unterminated Fiber By The Foot
The QT-40G-QSFP-850NM-300M-CSR4-MP is a parallel 40Gbps Quad Small Form-factor Pluggable (QSFP) optical module that provides increased port density and total system cost savings. The QSFP is full-duplex optical module offers 4 independent transmit and receive channels, each capable of 10Gbps operation for an aggregate bandwidth of 40Gbps 100m on OM3 Multimode Fiber (MMF) and 150m on OM4 MMF.
An optical fiber ribbon cable with an MPO/MTP connector at each end plugs into the QSFP module receptacle. The orientation of the ribbon cable is “keyed” and guide pins are present inside the module’s receptacle to ensure proper alignment. The cable usually has no twist (key up to key up) to ensure proper channel to channel alignment. Electrical connection is achieved though a z-pluggable 38-pin IPASS® connector.
The module operates from a single +3.3V power supply and LVCMOS/LVTTL global control signals such as Module Present, Reset, Interrupt and Low Power Mode are available with the modules. A 2-wire serial interface is available to send and receive more complex control signals and to obtain digital diagnostic information. Individual channels can be addressed and unused channels can be shut down for maximum design flexibility.
The QT-40G-QSFP-850NM-300M-CSR4-MP is designed with form factor, optical/electrical connection and digital diagnostic interface according to the QSFP Multi-Source Agreement (MSA). It has been designed to meet the harshest external operating conditions including temperature, humidity and EMI interference. The module offers very high functionality and feature integration, accessible via a two-wire serial interface.
FEATURES
- 4 independent full-duplex channels
- Up to 11.2Gbps per channel bandwidth
- Aggregate bandwidth of > 40Gbps
- MTP/MPO Male optical connector (Requires a Female MPO/MTP Connector with Method B Polarity)
- QSFP MSA compliant
- Digital diagnostic capabilities
- Capable of over 300m transmission on OM3 MMF (Multimode Fiber) and 400m on OM4 MMF
- CML compatible electrical I/O
- Single +3.3V power supply operating
- TX input and RX output CDR retiming
- Built-in digital diagnostic functions
- Temperature range 0°C to 70°C
- Silver with Beige Tab
- RoHS Compliant Part
Applications:
- Rack to rack
- Data centers
- Metro networks
- Switches and Routers
- Infiniband 4x SDR, DDR, QDR
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Product Reviews (19)
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M Kramer
LANshack's customer service and tech support is great! Easy to work with and the products were delivered on time!
Guest
Great product and service
customer
Easy to work with and shipment came exactly as ordered.
Eric S.
Item was what I ordered, came well packed.
FARLENG
Very good experience and delivered quickly and easily.
Don’t Just Take Our Word For It
Mar 30, 2026
Product was as ordered and delivered in…
Product was as ordered and delivered in a timely manner. Worked perfectly. Will use again in the future.
Brian Rich
Apr 15, 2026
Great Customer Service and received the…
Great Customer Service and received the product faster than expected.
customer
Nov 25, 2025
Product was as advertised
Product was as advertised. Shipping was on timeJohn Olson
JO
Dec 23, 2025
Excellent company with great speed
Excellent company with great speed, accuracy of products provided and very easy to work with in my experience.
Cline Electric
Jan 07, 2026
Great company great items
Great company great items
Joseph Leone
Apr 17, 2026
Great prices ++
Great prices, quality and delivery speed
thanks
george
George
Apr 14, 2026
Great Custom Cables
Great product, exactly what I needed and fairly quick shipping considering they are custom cables! Will definitely be ordering more.
Matt S
Apr 04, 2026
They do what they say
They do what they say. No BS
gavin714
May 30, 2026
Excellent Customer Service and Resolution
Tom personally reached out to me, took ownership of the situation, and worked to get my order resolved. He communicated with me directly, ensured the order was shipped, refunded the shipping charges, and provided a discount for the inconvenience.
What stands out most is the level of customer service and accountability shown throughout the process. It is refreshing to see a company stand behind its customers and make things right when an issue occurs.
I received my cable, the issue has been resolved, and I appreciate the effort Tom and his team put into correcting the situation. Based on how this was handled, I would not hesitate to do business with LANshack again.
Thank you, Tom, for your professionalism and commitment to customer service.
Lstargel
Apr 08, 2026
everything worked as expected
everything worked as expected. Nice pull sock set up.
customer
May 05, 2026
Superior product/ Superior service
It was particularly useful to me that I was updated regularly about the status of my orders. The products that I purchased were superaltive in every way and exceeded my expectations...
Dr. Craig Smestad
May 07, 2026
Products were available and ready to…
Products were available and ready to ship quickly. Products worked as they were supposed too.
Robert Butler
Feb 10, 2026
Great products
Best RJ45 crimpers!
Dave
Dec 09, 2025
Great team.
Open and clear lead times which they met or exceeded expectations. Quality product.
JC
Dec 30, 2025
Quick shipment
Quick shipment. custom quality cable!
Irwin Spector
Dec 23, 2025
The product was exactly as ordered
The product was exactly as ordered. The only criticism would be a real-time line on shipping and expected delivery.
D. L.
Feb 17, 2026
LANshack: Best custom CAT8 ethernet cable on the market!
I needed a custom 55 foot S/FTP (Shielded Foiled Twisted Pair) CAT8 indoor ethernet cable for ethernet backhaul between two Eero mesh routers. I did tons of research (including Grok) and I came across LANshack.com. They have the thickest 23AWG wire in their custom CAT8 cable vs 26AWG on Amazon (lower number is thicker; 23AWG wire has roughly twice the cross-sectional area of 26AWG). Excellent price per foot, and this cable is thick! Very quick turnaround once you order from them. I am very pleased with LANshack and I will order from them again for future projects!
Daniel T.
Apr 02, 2026
Easily ordered exactly what I needed
Easily ordered exactly what I needed. Once I got a shipping label item was delivered quickly and was packaged nicely. Would order from here again.
customer
Feb 25, 2026
fast service and excellent product
fast service and excellent product
JC STRAND
Feb 27, 2026
LANshack is the BEST!
Online ordering process was quick and easy. We are a non-profit organization and the LANshack team made the tax exemption process quick and easy. Fast shipping is especially appreciated! Thanks so much!
Non-Profit Customer
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