Product material: space aluminum Product practical points: 1. The diameter of the inner column is 3.5 mm. Please ensure that the inner diameter of your keyhole is larger than 3.5 mm. 2, the inner column is 15 mm high (can hold 2-10 ordinary keys, there is silicone gasket protection between the keys, it will not shake freely, neat and beautiful), if you have special keys, please measure them in advance. 3, the cross key can be installed (thickness is equal to 3-4 ordinary keys) black plastic head key can be installed, the electric iron dissolves the plastic supplement, most of the metal parts are perforated, but it does encounter If there is no hole in the metal part of one side, please grasp it yourself.