Specifications:- Size of Pin Back(Dia.xH): 7/8" x 1/8" (23 x 2.5 mm)- Size of Metal Shell(Dia.xH): 15/16" x 1/8" (24 x 3.2 mm)- Material: Iron, Abs- Mylar Film Diameter: 1 3/8" (35 mm)- Recommended Paper Type: 100g/square meter to 157g/square meter- Net Weight: 1.87 Lbs (0.85 kg). Package Contents:- 500x Metal Button Covers- 500x Plastic Button Pin Backs- 500x Transparent Mylar Films