Pelican cases are kept watertight through the use of a tongue and groove fit and a polymer o-ring. * Pelican cases come standard with an Automatic Pressure Equalization Valve which releases built up air pressure while keeping water out. * Pelican"s Pick N"Pluck foam lets you customize the interior. * Stainless steel reinforced padlock protectors * Interior Dimensions (inches): 21.78 x 16.69 x 10.62