General description Expert Quality 40 Piece Mechanics Bit Set featuring a variety of insert bits made from S2 silicon steel, which are hardened and tempered with a shot blasted finish. The set includes bit holders crafted from chrome vanadium steel, ensuring durability and strength. Technical specifications Contents: 1 x Bit holder 10mm hexagon x 3/8" sq. drive 1 x Bit holder 10mm hexagon x 1/2" sq. drive 7 x Draper TX-STAR® bits, 30mm: T20, T25, T30, T40, T45, T50, T55 7 x Draper TX-STAR® bits, 75mm: T20, T25, T30, T40, T45, T50, T55 5 x Spline bits, 30mm: 5, 6, 8, 10, 12mm 5 x Spline bits, 75mm: 5, 6, 8, 10, 12mm 7 x Hexagonal bits, 30mm: 4, 5, 6, 7, 8, 10, 12 7 x Hexagonal bits, 75mm: 4, 5, 6, 7, 8, 10, 12mm Other information Spare bits are available. Packed in a sturdy steel case for easy storage and transport.