This First Alert UL classified media protection chest is tested to withstand an external temperature up to 1550deg F for 1/2 hour and independently verified to protect electronic media, such as memory sticks, CDs, DVDs and external hard drives. Chest is waterproof even when fully submerged. Mount Type: Portable, Material: Steel w/ plastic cover, Lock Type: Key, Dimensions W x D x H (in.): 6 5/16 x 14 5/16 x 11 1/2, Door Thickness (mm): 25