The 1590Z235 is a Watertight Heavy Duty Electronic Instrument Enclosure made of rugged die-cast aluminum alloy with natural finish. Two piece "tongue & groove" construction with one piece silicone rubber gasket provides protection against access of dust and water. Four recessed stainless steel machine screws secure lid into tapped holes. Easy to wall mount using "through box - blind hole" construction, outside of gasket protection. Lid screws are self captivating (lid holes are threaded with the first installation of lid screws).