Construction: Drawn steel housing. Socket: Medium base porcelain socket with nickel plated copper screw shell. Aiming: 90° vertical aiming capability and 358° rotation. Adapter Copper alloy contacts provide precise spring action. True, positive electrical ground. On/off switch included. Patented embossed polarity arrows on bottom of adapter. Spring-loaded locking latch with embossed polarity arrows secures trac light to trac. Compatible with both Trac-Lites and Trac-Master Trac. “Pull-up” contact to up position for use on Trac-Master two-circuit trac. Labels: UL/CUL listed.