This set of 3 collet reduction sleeves are designed to allow 1/4" shank bits to be used in an 1/2" collet, 8mm shank bits to be used in a 1/2" collet and 1/4" shank bits to be used in an 8mm collet. 

Each sleeve has been precision machined from a single piece of steel to ensure accuracy and therefore a firm grip on the router bit. ©