The 1550Z137 is a square, deep, thick-wall watertight diecast aluminum enclosure measuring 4.76 in x 4.76 in x 4 in (121 mm x 121 mm x 102 mm). Its 4.02 in (102 mm) total depth with a 0.83 in (21 mm) lid height gives room for taller components and connectors, making it a fit for instrument builders, integrators and electricians. This unpainted version is vibra finished for a smooth surface with no sharp edges.

According to the drawing, the inside measures 111.27 mm [4.38 in] in length and width with an inside depth of 96.70 mm [3.81 in]; the maximum P.C. board size is 110.12 mm x 110.12 mm. The diecast aluminum alloy is tough yet easy to machine, and the walls have no internal ribs.

The lid is secured with four stainless steel Philips head M4 - 0.7 machine screws. On the 1550Z137 these screws are self-captivating: lid holes are slightly undersized and threaded with the first installation, so screws stay with the lid. They sit outside the silicone gasket, and the recommended torque is 5-7.5 lbf.in (50-75 cN.m). Blind thru-box holes allow wall mounting with access outside the gasket ring, and the box accepts a #6 self tapping ground screw.

The 1550Z137 is rated IP68, NEMA 4, 4X, 12 & 13 and IK08 per IEC62262, is cUL and UL listed under file #E71073, and is RoHS and REACH compliant. It ships shrink wrapped with box, lid, silicone gasket and 4 cover screws at 1.72 lbs (0.78 kg).