Wera 8551 premium plus impaktor diamond bits for pozidriv screws wera 05073922001 this 14in hexagon drive impaktor diamond pz3 screw bit from wera is suitable for use with impact screwdrivers and power tools these high strength bits are easily recognisable due to their black colour wera 05073922001 8551 premium plus impaktor diamond bit for pozidriv screws pz3