Cisco WS-X4148-RJ network switch module

catalyst 4000 10 100 Auto Module  48-Ports RJ-45
This module provides 48 ports of dedicated 10/100 Ethernet switching for Ethernet or Fast Ethernet client or server switching. All ports can utilize Fast EtherChannel technology for higher-speed uplinks or server connections.It can be used in conjunction with any of the other Catalyst 4000 modules, making the Catalyst 4000 a flexible and expandable switching option.