This product is either discontinued or we cannot get that from suppliers.
Cisco WS-C3850-12XS-E Catalyst 3850 12 Port 10g Fiber Switch, 1 RU, Network C3850-NM-4-10G, 12 x 10/100/1000 10G SFP+ Optical ports, Stack bandwidth 480 Gbps, Performance 227.28Mpps, Switching Capacity 320Gbps, RAM/Flash Memory 4GB.
WS-C3850-12XS-E switch provides 12 ports 10Gbps SFP+ connection with upgradeable IP services image and build in wireless controller provide fully convergence between wired and wireless on a single platform.