The Cisco 40GBASE-LR4 QSFP module supports link lengths of up to 10 kilometer over a standard pair of G.652 single-mode fiber with duplex LC connectors. The QSFP-40G-LR4-S module supports 40GBase Ethernet rate only. The 40 Gigabit Ethernet signal is carried over four wavelengths. Multiplexing and demultiplexing of the four wavelengths are managed in the device.

Operational conditions
Operating temperature (T-T)	0 - 70 °C
Storage temperature (T-T)	-40 - 85 °C
Operating relative humidity (H-H)	10 - 80%
Storage relative humidity (H-H)	10 - 85%
Certificates
Certification	MSA
Packaging content
Quantity per pack	1 pc(s)
Performance
SFP transceiver type	Fiber optic
Maximum data transfer rate	40000 Mbit/s
Interface type	QSFP
Single-mode fiber (SMF) supported	Yes
Fiber optic connector	LC
Fiber cable diameters supported (core/cladding)	9/125 µm
SFP transceiver standard	LR
Maximum transfer distance	10000 m
Wavelength	1310 nm
Networking standards	IEEE 802.3ba
Cabling technology	40GBASE-LR4
Auto MDI/MDI-X	Yes
Features
Hot-Plug support	Yes
Logistics data
Harmonized System (HS) code	85369010