12.7MM SATA to SATA 2nd Hard Drive SSD HDD Module Caddy Adapter for IBM T420 T430 W520 W530 T520 T530 Height: 12.7MM Interface: SATA to SATA Interface:SATA(internal,connect to hard disk)-SATA(external,connect to your laptop) Compatible: T420 T430 W520 W530 T520 T530