X2 10GB SR
X2 10GB SR Cisco module is a multimode transceiver target at the 10G applications. It works with 850nm multimode fiber and the optical interface is duplex SC. X2 10GB SR can link the equipment to fiber optic networks, max transmission distance is 300meters.

X2 10GB LR
X2 10GB LR fiber optic transceivers by Cisco are single mode modules max working distance is 10km. they are 10GB transceivers that are fully compatible with IEEE standards.