The 1551TFLBK is the 60 x 60 x 20 mm 1551T enclosure in black ABS, supplied with a lid that has mounting flanges molded in. Across the flanges it measures 76.30 mm (3.00 in), giving a simple way to screw it to a wall or suspend it with a tie wrap. It houses a PC board up to 54 x 54 mm.

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 1551TFLBK measures 2.36 in x 2.36 in x 0.79 in (60 mm x 60 mm x 20 mm), with the length of 60 mm quoted not including the flange; overall length across the flanged lid is 76.30 mm [3.00 in]. The maximum PC board size is 54 mm x 54 mm, and the shipping weight is 0.06 lbs (0.03 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 1553WTS100 (Plastite self-tapping #2 x 3/16" (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.