Galvanized metal construction for the side panels and perch brackets. Plastic for the top, front and back panels and perches of the D2S, D4S and D6S models. Comes with removable plastic nest bottoms for easy cleaning. Nuts and bolts construction for D2S, D4S and D6S models. Will need rivet gun for the D8S and D10S models (not supplied). Shipped knocked down. Front opening 7" x 11 1/2", Experts recommend 1 nest box per each 4 laying hens. Zoned shipping charges will apply to these Conventional laying nests. Perch design change per manufacturer. Photos do not show current production.