2.5" External Mobile Solution with 4200RPM 80GB USB 2.0 Firewire 400 Combo Capacities 100GB, PATA Interface, Sustained data transfer rates up to 23MB/sec, 1.5 ms average seek time, 133MB/sec max bus speed, 8MB Cache Buffer, S.M.A.R.T. compliance features 4200 RPM Oxford Chip Set for Macs USB 2.0