The 1551XTBU is a translucent blue general purpose ABS plastic miniature hand held enclosure measuring 80 x 80 x 20 mm (3.15 x 3.15 x 0.79 in) including the lid. It is aimed at OEM engineers, hobbyists and product designers who need a compact housing for a small printed circuit board or a ready-made box for potting electronics.

The 80 x 80 mm square footprint is the widest in the 1551 range, and at 20 mm deep including the lid it takes square boards up to 74 x 74 mm with room for taller parts. Inside, the box measures 76.00 x 76.00 mm [2.99 x 2.99 in], and the drawing gives a maximum PC board size of 74.04 x 74.04 mm [2.91 x 2.91 in]. PC board standoffs are molded into the interior and accept #2 self-tapping screws; the recommended board screw is #2 x 3/16", which is not included.

The box is molded in translucent blue ABS and the lid is held by four #4 x 1/2" self-tapping screws, black plated to match. Recommended screw torque is 35-43 ozf.in (25-30 cN.m). The same size is offered as 1551XBK, 1551XGY in the other colours.

Walls are 2 mm (0.08") thick and the lap joint between box and lid protects against dust and splashing water; the enclosure is designed to meet IP54 and carries a UL94 HB flame rating. The 1551XTBU is RoHS and REACH compliant, ships in a bag with the box, lid and 4 cover screws, and has a shipping weight of 0.09 lbs (0.04 kg). Some chemicals, such as acetone, thread-locking compounds and cutting fluid, can damage ABS, so check compatibility before use.