The Makita MAKP51954 4 Piece Fast Change Drill & Countersink Set, also known as 'Screwsinks or Screwdiggers'. This high quality set is ideal for tradesmen, craftsmen, carpenters and fitters, and should help the novice DIY'er achieve a more professional job. The 4 sizes included in this set cover virtually all of the most commonly used screw sizes, from No. 6 (metric size 3.5mm) which is a popular size with the furniture industry, right up to No. 12 (metric size 6mm) which are used for frame fixings and large construction work. Sizes No. 8 (metric size 4mm) and No. 10 (metric size 5mm) are arguably the most commonly used size screw heads at home as well as on the building site and they are available in a multitude of lengths. Contains: 1 x No.6 Size Countersink with 3/32in Pilot Drill. 1 x No.8 Size Countersink with 7/64in Pilot Drill. 1 x No.10 Size Countersink with 1/8in Pilot Drill. 1 x No.12 Size Countersink with 1/8in Pilot Drill. 1 x Hexagon Key.