The 1590ZGRP263BK is the longest format in this group at 601 mm, with a 250 mm width and 121 mm assembled depth. It is built for long PC boards or long inner-panel layouts that need a watertight, impact-resistant housing, and is molded from black glass reinforced polyester with a smooth finish and thick walls.

The body is 96 mm deep with a 26 mm lid; the part page gives 600 x 250 x 120 mm. Inside, the drawing shows about 587.75 mm of length, 236.65 mm of width and 109.00 mm of height. The molded-in internal shelf accepts a PC board up to 582.65 x 232.64 mm or the 1590ZGRP263PL galvanized steel inner panel, sold separately.

Unlike the smaller sizes, this enclosure's purchased assembly includes six cover screws, along with the box, lid and gasket. The self-captivated stainless steel screws should be torqued to 13.3-17.7 lbf.in (150-200 cN.m). The lid uses two piece tongue and groove construction and a silicone sponge gasket; wall mounting through holes are outside the gasket channel.

It is IP66 and NEMA 1, 4, 4X, 12 & 13 rated, certified to NEMA 4, 4X per UL 508A, cUL & UL listed under file E65324, UL94 V-0 flame rated, and IK09 impact rated per IEC 62208 and IEC 62262. Recommended operating temperature is -40°C to +100°C; shipping weight is 10.99 lbs (4.98 kg).