With dimensions of 20 x 21.5 mm (0.79 x 0.85 inches), the MiniSD is considerably smaller than conventional SD cards. But other than the mechanical write protect switch, it's identical to its larger parent. Its thickness is also reduced, from 2.1 mm (0.08 in) to 1.4 mm (0.06 in). To access its contents on a PC, you'll need an adapter that can accommodate a MiniSD card. Maximum capacity for MiniSD cards currently tops out at 1 GB.