aluminum alloy with a texture on thesurface, our drill stopper features a nylon inner that locks firmly in place to wear and tear on your drill bit The nylon inner is easy to, not loose, and effectively avoids wear on the locking part of the drill bit The outer is aluminum alloy, which is, beautiful and lightweight Thesurface has anti slip patterns and can be manually tightened, making it simple and practical The inner diameter of the limiter can be adjusted and fixed at different positions on the drill bit, accurately controlling the drilling depth Achieve precise drilling depth with ease using our adjustable drill stopper the perfect tool for enthusiasts and professionals alike, Manufacturer: Hsyzygian