Made of good quality iron and zinc plated finish, anti-corrosion and durable to use. Keyhole hangers can be used to hang artwork, plaques, wall decor, picture frames and mirrors, etc. Easy to install by screws. Mounting screws are included here. Specification:Material: IronFinish: zinc platedPlate Thickness: 1.4mm / 0.055"Mounting Hole Diameter: 4mm / 0.16"Keyhole Size: 17.5mm x 9.5mm / 0.689" x 0.394" (L*Max.D)Screw Size (+/-1mm): 3mm x 12mm / 0.12" x 0.47" (Threaded.D*L)Total Size: 42mm x 16mm x 2.5mm / 1.65" x 0.63" x 0.098" (L*W*H) Package Content: 50(+/-2%) x Keyhole hangers100(+/-2%) x Screws