The 1551SFLBK is a low-profile 50 x 50 x 15 mm black ABS enclosure whose lid includes molded mounting flanges. Overall length across the flanges is 66.30 mm (2.61 in), and the inside height is 10.99 mm, so it suits thin circuit boards up to 44 x 44 mm that need to be fixed to a wall or cable-tied in place.

The body is molded from general purpose ABS plastic with 2 mm (0.08 in) walls and carries a UL94 HB flame rating. Lap joint construction between box and lid protects against dust and splashing water, and the enclosure is designed to meet IP54. PC board mounting bosses are molded into the interior and accept #2 self-tapping screws. The black colour is specified as RAL 9011.

Outside, the 1551SFLBK measures 1.97 in x 1.97 in x 0.59 in (50 mm x 50 mm x 15 mm), with the length of 50 mm quoted not including the flange; overall length across the flanged lid is 66.30 mm [2.61 in]. Inside dimensions are 45.12 mm [1.78 in] long, 45.12 mm [1.78 in] wide and 10.99 mm [0.43 in] high. The maximum PC board size is 44 mm x 44 mm, and the shipping weight is 0.05 lbs (0.02 kg).

Each flanged assembly includes the box, the lid and 2 self-tapping #4 x 1/2" cover screws, black plated to match the enclosure; the recommended torque is 35-43 ozf.in (25-30 cN.m). Screws for securing the PC board are not included; the drawing lists part 1551ATS100 (#2 x 3/16" self-tapping (4.8 mm), pack of 100). The part is RoHS and REACH compliant and ships in a bag.

Hammond notes that some chemicals can damage or weaken ABS, including acetone, ketones, thread-locking compounds and cutting or tapping fluids, so check compatibility before cleaning or modifying. The enclosure can be factory modified (milling, drilling, printing) and solid models are available in .stp or .x_t format.