This is an genuine OEM sourced replacement part used on routers. This part provides a grip for holding a bit in a tool. It is made out of metal and is sold individually. This collet is for using bits with 1/4" arbors only. Due to prolonged, heavy use a collet adapter may need to be replaced eventually. To replace this item you would nee...Read mored to use a Wrench. • First you would need to remove the collet nut • Once the nut is removed you can remove the old collet adapter • Place a new one in place • Tighten the collet nut back in place and your unit is ready to use 1/4" bits