The Kincrome Micro Impact Screwdriver Set is designed specifically for effective fastening and loosening of rusted, damaged or stripped fasteners in light-duty applications, such as smaller fasteners used on a car or motorbike. It does this by applying a strong, sudden rotational force coupled with forward thrust when struck with a hammer to 'shock' fasteners loose and prevent the tip from camming out of the fastener. Unlike other Impact Screwdrivers it utilises Kincrome PTA 1/4" hex drive bits and features a knurled steel body for added grip and a steel end-cap for striking with a hammer. To use the impact driver, simply select the Kincrome PTA bit that suits the application, place the tip into the fastener and apply light rotational pressure in the direction that you wish to turn the fastener in order to engage the tool mechanism. maintain light rotational pressure and strike the end-cap with a hammer using your other hand. A few hits should tighten or loosen the fastener as required.