... 1.High precision & good matching 2.Compact resistance 3.Waterproof 4.Real factory Best sheet metal extruded aluminum ... service and very super precision reach to 0.001mm.3.Standard mold base.4.Send sample with test video ... pinions, wheels ) bearing, bearing seat, spring, connector, socket, bushing, push-button, etc.Surface Finishannealing, natural anodization, heat treatment, polishing, nickel plating ...