Plastic grip knobs are designed to provide a positive, non-slip grip, these knobs are ideal where a firm fastening action is required. Gripping surface is available in 3 versions; “ribbed”, “knurled”, or “fluted”. Gripping surface is comfortable and free of any sharp, uncomfortable edges. A large selection of insert or stud materials are available including, but not limited to: steel, brass, stainless steel, and zinc plated.