The 1591EF2SBK is the black economy version of the 1591E bottom-flange enclosure, listed in the series table at 190 x 111 x 61 mm (7.48 x 4.37 x 2.40 in). It gives OEM builders and installers a larger flanged box for circuit boards at the general purpose material grade.

Economy versions are molded from general purpose plastic and are not flame retardant; the part page lists UL94 HB. The lid is held by six #4 self-tapping screws into fully plastic posts, black to match the box, with a recommended torque of 42-57 ozf.in (30-40 cN.m). Lap joint construction and an IP54 design protect against dust and splashing water.

The drawing gives 220.00 mm (8.661 in) overall length with the flange and inside dimensions of 183.52 x 103.53 x 56.60 mm (7.225 x 4.076 x 2.228 in). Card guides molded into all side walls accept 1.5 mm (0.062") boards, and 1591Z adaptors allow horizontal mounting.

The 1591EF2SBK weighs 0.53 lbs (0.24 kg), ships shrink wrapped with box, lid and 6 cover screws, and is RoHS and REACH compliant. Replacement screws are 1591TS100BK (black) or 1591TS100 (nickel plated).