The Starrett KDC05021 Electrician's Holesaw Kit contains a selection of sizes to cover a variety of different jobs. Deep Cut Bi-Metal Holesaws offer aggressive material penetration and kerf clearance. Improved tooth material for enhanced heat and wear resistance and greater product life. Ideal for solid materials or tubes with a wall thickness greater than 3mm. The 51mm cutting depth improves cutting performance on tubes, particularly where there is a need to cut through both sides of the tube. Suitable for all tradesmen, installation engineers, industry generally and the DIY enthusiast. Packed in a sturdy EVA carry case. Contains: 5 x Holesaws: 20, 25, 29, 44, 51mm 2 x Arbors: A1, A10