Secure Digital cards are solid-state devices designed with flash technology, a non-volatile storage solution that does not lose its information when power is removed from the card. The cards contain no moving parts and are extremely rugged, providing much greater data protection than conventional magnetic disk drives.

The SD card's nimble, portable data transfer and low battery consumption makes it ideal for high-speed digital cameras, camcorders, MP3s, cell phones, PDAs, and global positioning systems. Interface options include an SD interface or a serial peripheral interface.

Crucial SD cards measure 0.95 inches wide, 1.26 inches high, and 0.08 inches thick (24 mm by 32 mm by 2.1 mm).