High quality 1/2"D impact driver, for 5/16" hex bits, designed to deliver a strong, sudden rotational force and forward thrust when struck with a hammer to release stubborn fasteners. The two-way impact mechanism has a twist/lock clutch adjuster for clockwise and anti-clockwise use. Set includes thirteen bits including, Phillips, Flat and Hex, neatly presented in a blow mold storage case making it easy to find the right bit for the job.