The hinges are made of brass and are suitable for mounting on wooden boxes, cabinet doors, etc.The plate to be installed must have a circular edge.When fixing the hole, it must be fixed with fixing glue.Spercification:Product Name: Cylinder HingeMaterial: CopperTotal Dimension: 15 x 4mm / 0.59 x 0.16 inch(L*D)Drilling Hole Diameter: 4.2mm Package Content:50pcs x Cylinder Hinge