Wiring troughs enclosure made of 16 ga plated steel. Keyhole screw slots in cover. Shipped completely assembled no end caps to install. Mounting holes on the back of the enclosure. Flat cover fastened with plated steel screws. No gasketing or knockouts. Using a unique joining method that mechanically locks components together without fasteners or heat, this wiring trough ships completely assembled to save both time and labour. Designed for indoor use, this trough is available in various lengths.