The 1591MSBK is a black 1591M plastic enclosure without mounting flanges, the low-profile 26 mm version of the 85 x 56 mm footprint. It is aimed at designers of small electronic assemblies who want a compact box with card guides molded into all side walls, accepting 1.5 mm (0.062 in) printed circuit boards mounted vertically.

This is the economy version, molded from general purpose ABS rated UL94 HB and not flame retardant. It keeps the lap joint box-to-lid construction that guards against dust and splashing water and is designed to meet IP54. The lid is secured with self-tapping screws driven into fully plastic posts, and the black finish comes with black screws.

Nominal size is 3.34 in x 2.2 in x 1.03 in (85 mm x 56 mm x 26 mm). The drawing gives an inside length of 78.63 mm [3.096 in], inside width of 51.83 mm [2.041 in] and inside height of 20.90 mm [.823 in], with a guide height of 15.90 mm [.626 in] and a slot width of 2.07 mm [.082 in].

Each 1591MSBK assembly includes the box, lid and 4 cover screws; recommended cover screw torque is 42-57 ozf.in (30-40 cN.m). Shipping weight is 0.1 lbs (0.05 kg), and the part is RoHS and REACH compliant. For horizontal board mounting, 1591Z card adaptors are offered.