Features: 1. This set includes 4 standard plug cutters and 4 four-tooth chamfered cutters. 2. Chamfered cutters make tapered plugs to fill countersunk holes, convenient to use. 3. Use stan dard cutters to eliminate imperfections in wood, practical tools. 4. 8 Piece plug cutter set makes perfect plugs for counter-bored holes, reasonable design. 5. The cutter set achieves excellent finish when using same timber. 6. Suitable for bench drill and hand electric drill, recommended bench drill, round shank. Specification: Condition: 100% Brand New Material: Carbon Steel Application: Bench drill and electric hand drill accessory Bit Size: 6mm/10mm/13mm/16mm (1/4" 3/8" 1/2" 5/8") Shank: Round Shank Diameter: 10mm 1/4: Wood Diameter: 6mm / 0.2in, Wood Length: within 22mm / 0.9in 3/8: Wood Diameter: 10mm / 0.4in, Wood Length: within 23mm / 0.9in 1/2: Wood Diameter: 13mm / 0.5in, Wood Length: within 25mm / 1in 5/8: Wood Diameter: 16mm / 0.6in, Wood Length: within 26mm / 1in Package List: 8 * Wood Plug Cutter Note: The speed of the drill should not be too fast, fast speed will cause smoking, etc.