Power drills are an essential tool in the workplace or in the home. There are several different types of electric hand-held power drills; the pistol grip, the hammer drill - including rotary hammer drills - angle drills and cordless drills. Pistol grip drills are the most common type of hand-held drill. Many different types of attachment can be purchased to alter the function of a basic pistol grip drill, such as a boring device, an orbital sander or even a hand saw. Hammer drills are used for drilling concrete, brick and stone: the hammer mechanism allows heavy use on hard materials without damage. A rotary-style hammer drill offers more versatility as it can be used as either a hammer or a spinning drill. Cordless drills are powered by a rechargeable battery pack and are useful for outside work where there is no power outlet. Good quality models feature a rapid charging device and as much as 36 volts of battery power to allow for long periods of continuous use. Distrelec supplies a wide range of power drills from well-known brands, including Bosch, Kress and Skil. The models have varying features, such as levels of power consumption, no-load speed and no-load hammer rate.