2-port 1GBASE-T module provides 2 dual-speed 1BASE-T or 1GBASE-T RJ-45 ports; can also be used for low cost stacking. For use with HP 512 EI, 55 SI, 55 EI, and 55 HI switches. 1m over Cat 7 or Cat 6a. : Up to 1m distance using RJ-45 copper.*55m over Cat 6 / Cat 5e IRF stacking scalablility: work with HP IRF stacking cable to provide virtual chassis solution