the PA-T3 serial port adapter is a single-width, one-port module that integrates data service unit (DSU) functionality into the Cisco router.are available on Cisco 7200 series routers, Cisco 7301routers,Cisco 7401ASR routers;on second-generation Versatile Interface Processor (VIP2) in all Cisco 7500 series routers;on the Catalyst 6000 family FlexWAN module in the Catalyst 6000 family switches. good working and physical condition 120day warrenty