Size : 12mm, 16mm, 19mm; 1/4" round shank fits all handheld and stationary drills.Ideal for Wooden planks, Fiberboard, Particle board, Plywood, Plastic, etc.Five-flute design reduces vibration for smoother drilling and extended bit life.Great for sinking 90 degree holes into wood and plastic countersink screws and fixings.With standard high speed steel and super hard titanium coated bits for increased durability and corrosion resistance.