Sufficient quantity: package includes 100 pieces pin keepers and 10 pieces locking tools. Full sized slim profile sets are provided to meet all needs. Durable and exquisite: the locking backs are made of plated copper, rendering them completely rustproof and extremely durable. Size information: the pin keeper diameter is 6 mm / 0.24 inch, the height is 5 mm / 0.2 inch, and the screw length is 3 mm / 0.12 inch, sufficient to lock the pins firmly in place. The locking tool is 4.5 cm / 1.8 inches. Keep your pin in place: the locking pin keepers will secure pins on leather, vest, jacket, cap, hat, work uniform, lanyard, bags, badges, and virtually any garment. Easy to attach: just put a pin keeper in the back of your favorite pin, then use the locking tool to secure it in place. The whole process is quick and effortless, ideal for those who enjoy wearing pins.