The 13 PCE Impact Bolt And Nut Remover Set (1/4"-11/16") (8mm-19mm) is manufactured from chrome molybdenum for increased durability. Designed for the safe removal of bolts that have rounded off, rusted or painted over. Suitable for hand and power tools. Can be used with 3/8†breaker bar/ratchet and also has flats so that they can be used with spanners or wrenches. Complete with a useful carrying case for quick and easy storage.