Description: Color: primary color, golden Material: carbon steel + high speed steel Dimension: 5 1.98mm(0.07795 inch)x 50mm(L) 6 2.38mm (0.0937 inch) x 55mm(L) 8 2.78mm (0.1094 inch) x 60mm(L) 10 3.175mm (0.125 inch) x 63mm(L) 12 3.56mm (0.14 inch) x 65mm(L) Specification: Standard 1/4 Inch hex shank is quick change compatible. Drill and countersink for wood screws without changing bits. Special designed steel counter sleeve countersinks or counter bores pilot hole. Drilling length can be adjusted for various length screws simply by loosening and tightening the setscrew. Suitable for soft metal, insulation board, PVC board, wood board, etc. includes: 1 xCountersink Drill Bit Set( 5pcs or 4pcs included)