The DEWALT Extreme Masonry Drill Bits offer excellent quality for all types of masonry work. They last up to 2 times longer and deliver up to 50% more holes per charge on a cordless drill than a standard masonry bit. Optimum carbide grade maximises durability. A unique tip design provides an efficient drilling action and reduced walking for greater accuracy. Optimised milled flute offers fast drilling and the special copper brazing withstands high temperatures. Applications: Typically used for drilling anchors, plastic plugs, fixings or pipework clearance holes. Suitable for masonry, brick, stone, tiles and light concrete. This DEWALT Extreme Masonry Drill Bit has the following specification: Diameter: 4mm.Overall Length: 75mm.Working Length: 50mm.