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): 21.37 x 16.31 x 12.56 Retractable extension handle 4 strong polyurethane wheels with stainless steel bearings Easy open double throw latches Open cell core with solid wall design - strong, light weight Stainless steel hardware and padlock protectors