SD Card Logging Shield for Arduino (2 Pack)Most Arduino boards have limited onboard memory storage. The SD card logging shield allows expanding the storage to up to 2 GB.Specifications Voltage: 3.3V - 5V Protocol: SPI Dimensions: 2.05" x 1.18" x 0.47" (52 x 30 x 12 mm) Weight: 0.28 oz. (8 g) Required library: SD.h