The 1590ZGRP243PL is the inner mounting panel for the 400 x 250 mm enclosures in the 1590ZGRP series: the 1590ZGRP243 (120 mm deep) and the 1590ZGRP244 (160 mm deep), both of which list it in the ordering table.

The panel measures 15.04 x 9.13 x 0.06 in (382 x 232 mm). The drawing gives 16 gauge galvanized steel at 1.61 mm [.064 in] thick, with 1.00 x 45.0° chamfered corners. It fastens to the molded-in bonding/mounting nuts on the enclosure's internal shelf.

Panel mounting screws and washers are included with the 1590ZGRP243PL. Extra hardware is SCGM6GRP-20 copper ground hardware (20 pack, M6 - 1.0 x 6mm with M6 washers); the drawing names the SCGM6GRP copper plated M6-1.0 x 6mm mounting screw.

Hammond specifies a recommended panel screw torque of 45-50 cN-m [65-70 ozf-in]. The 1590ZGRP243PL is RoHS and REACH compliant, ships shrink wrapped at 2.26 lbs (1.03 kg). The drawing notes that factory modification (milling, drilling, printing etc.) is available and that solid models can be had in .stp or .x_t format. UL file E65324 is listed for the panel.