I bought cheap plastic but wasn't impressed. It's really nice, thick aluminum. SS mounting screws to close the top. Built-in seal, no need to install by yourself. Flat base for mounting on the roof of a van, hole drilled for a 2" conduit to pull cables through the base. 4 holes for roof mounting, approx 7/8" screws required for mounting. Didn't crack or do anything unexpected when drilling holes. No knockouts, this is what I was looking for in a waterproof junction box, ip66. Overall a good buy. I would recommend this for an RV roof mount for any wiring including solar. Exceeded my expectations.