High Quality/High Speed Premium High Capacity SD Memory Cards. Dimensions (LxWxH): 32mm x 24mm x 2.1mm. Operating Voltage: 2.7V - 3.6V. Operating Temperature 25ºC (-13ºF) to 85ºC (185ºF). Durability: 10,000 insertion/removal cycles. Fully compatable with Secure Digital 2.0 specifications. 4 GB.