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. Balances interior pressure, keeps water out Stainless steel reinforced padlock protectors. Minimum temperature -40° F (-40 ° C). Maximum temperature- 210° F (99 ° C) Interior Dimensions (inches): 20.00 x 20.00 x 20.00