Description: 4pcs Wood Plug Cutter/Cutting Drill Bit Set. Material: Carbon steel. Heat treated carbon steel for strength,Suitable for all hand and power drills. Contains four popular sizes of countersink bits :6mm, 8mm, 10mm, 13mm. Handle: Round shank ,Do not use the product for metalworking. Specification: Material: Carbon Steel Color: As picture show Package Includes: 1 Set Woodworking Cutting Tools Kit Set (4 Pieces) Note: Since the size above is measured by hand, the size of the actual item you received could be slightly different from the size above