11 PC R8 Collet Set 1/8"- 3/4" Bridgeport Mill Holder 1/8'' to 3/4'' R8 collet set ; 11 PC Set Sizes: 1/8'', 3/16'', 1/4'', 5/16'', 3/8'', 7/16'', 1/2'', 9/16'', 5/8'', 11/16'', 3/4'' .0006" TIR ; Drawbar Thread: 7/16"-20 Precision ground to close tolerance ; Hardened and ground throughout Quantity: 1 (11 pieces TOTAL) ; Shipping Weight: 8 lbs ; Made of highest grade steel available