The 1591ATRD is an IR Red translucent polycarbonate enclosure in the smallest size in the 1591T range, a slim 100 x 50 x 25 mm case. It is intended for small infrared-based electronics whose IR devices must work through the housing.

The IR Red version is almost totally transparent to infrared devices, making it a fit for circuits whose infrared devices sit behind the wall of the case. The case is molded from flame retardant translucent polycarbonate that is easy to machine, and lap joint construction between box and lid provides protection against access of dust and splashing water. It is designed to meet IP54 and is listed as RoHS and REACH compliant.

The drawing gives overall dimensions of 100.00 x 50.00 x 24.80 mm (3.937 x 1.969 x 0.976 in). Its 20.90 mm inside height and 43.83 mm inside width suit small, low-profile boards carrying indicators or sensors. Integral card guides accept 1.5 mm (0.062 in) PC cards, with a guide height of 15.90 mm and a slot width of 2.07 mm.

The purchased 1591ATRD assembly includes the box, lid, 4 cover screws and pre-installed brass inserts. The lid is secured with M3 x 10 mm Phillips machine screws threaded into integral brass bushings at a recommended torque of 42-57 ozf.in (30-40 cN.m); replacement screws are part number 1591MS100. The same size is also offered as 1591ATBU and 1591ATCL in the other translucent tints. Some chemicals can damage or weaken plastic, so check chemical compatibility before cleaning or modifying the case.