40GBASE-LR4 QSFP+ Optical Transceiver Module 4 Pack - 10km LC

In this review of the 40GBASE-LR4 QSFP+ Optical Transceiver Module 4 Pack, the bottom line is straightforward: networking teams who need reliable 40G links over single-mode fiber will find a cost-effective, tested option here. The modules are built for 10km LR4 links with a hot-pluggable QSFP+ form factor and include real-time digital optical monitoring, making them a practical choice for rack-level aggregation and data center uplinks where compatibility and diagnostics matter.

Key Features

• 40GBASE-LR4 support: Provides a standardized 40G single-mode fiber link engineered for up to 10km reach, suitable for campus and data center interconnects.
• Built-in DDM: Real time digital optical monitoring helps diagnose power and signal quality without external test equipment, speeding troubleshooting.
• Low power draw: With a maximum power consumption of 3.5W per module, the design supports denser deployments while limiting thermal load.
• Compatibility testing: Modules are validated in targeted switch devices and programmed in a compatibility lab to meet EEPROM coding expectations of leading vendors.
• 4 CWDM lanes: The MUX/DEMUX design and up to 11.2Gbps per channel bandwidth deliver the LR4 wavelength division multiplexing required for 40G performance.
• Standards compliant: Conforms to IEEE 802.3ba, SFF-8436 and QSFP MSA for predictable interoperability with compliant hardware.

Who It's For

This four-pack is aimed at network engineers and IT managers who need to upgrade or expand 40G uplinks without replacing switch hardware, and who value modules that have been tested for EEPROM compatibility and device-specific behavior. The included DDM is helpful for teams that will actively monitor link health and perform on-site diagnostics.

It is less appropriate for crews needing extended temperature tolerance beyond the commercial range, or for short-reach multimode environments where SR optics would be the correct choice. Buyers should also confirm switch compatibility lists, although the product is designed to meet common vendor EEPROM requirements.

Pros & Cons

Pros

• Tested compatibility and EEPROM programming reduce the chance of vendor rejection in many switch models.
• Built-in DDM provides live monitoring for optical power and diagnostics.
• Compact QSFP+ form factor with low 3.5W power consumption supports denser deployments.
• Compliant with major standards, aiding predictable interoperability.

Cons

• Commercial temperature range (0 to 70C) may limit use in extreme environments.
• Designed for single-mode LR4 links only; not suitable for multimode short-reach applications.

Specifications

Form Factor	QSFP+
Standard	40GBASE-LR4, IEEE 802.3ba
Wavelength	1310nm (4 CWDM lanes)
Reach	Up to 10km over SMF
Power Consumption	Max 3.5W
Temperature Range	0 to 70C (32 to 158F)
Connector	Duplex LC

Our Verdict

The 40GBASE-LR4 QSFP+ 4 pack is a pragmatic choice for IT teams that need reliable 10km single-mode 40G links with useful diagnostics and proven EEPROM compatibility. It offers strong value where commercial temperature operation and LR4 single-mode performance match deployment needs, providing straightforward integration into existing QSFP+-capable switches.

Frequently Asked Questions

Will these modules work with major switch brands?
They are programmed and tested for EEPROM compatibility with targeted switch devices, but buyers should verify their switch model list to ensure full interoperability.

What fiber connector do they use?
The modules use a duplex LC connector compatible with single-mode fiber for LR4 links up to 10km.

Can I monitor optical power remotely?
Yes. Built-in digital optical monitoring provides real-time metrics for power and link diagnostics.