You are buying 15mm Press Studs in a complete 4 piece set. These can be used on Leather Jackets, handbags, clothing,Denim Jeans, car hoods, boat covers, belts and straps etc. Size: Cap 15mm Outer Socket 14mm Outer Stud 11mm Post 11mm Post height is 7mm It comes in a set of 4 parts Part A - Cap for fixing socket Part B - Socket (female part of press stud) Part C - Stud (male part of press stud) Part D - Post for fixing stud