The catch is a double locking type with a silicone cover in platinum! It is not too tight or too loose, so you dont have to worry about it falling out. Now you can use the Dondon with peace of mind that you have lost the catch; Material: Pt Platinum 900; Size: Height: Approx. 0.2 inch (4 mm); Diameter: Approx. 0.2 inch (5 mm); Compatible with piercing cores of 0.7 mm or less; Catch are sold as a pair of earrings per order. These earrings are made by skilled craftsmen in our Japanese workshop.