GLC-LH-SM-PCW is a 1000BASE-LX/LH SFP Transceiver, generic for Cisco GLC-LH-SM. It is guaranteed compatible for all Cisco switch and router product lines. This transceiver can be mixed and deployed with Cisco OEM transceivers for seamless network performance and interoperability. PC Wholesale offers a LIFETIME advance replacement warranty on all transceivers (compared to 90 days from most OEM manufacturers).