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 standard 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. Features: 2. Chamfered cutters make tapered plugs to fill countersunk holes, convenient to use. 3. Use standard cutters to eliminate imperfections in wood, practical tools. 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: Note: The speed of the drill should not be too fast, fast speed will cause smoking, etc.