ZENTRO drill bits are manufactured in Germany by one of the “big three” producers of hammer drill bits in the world today. Stringent quality controls are obeyed through every stage of manufacture guaranteeing a quality finished product. PGM certified sizes carry the PGM approval mark which guarantees conformity to manufacturing parameters set out by the German Institute of Constructive Engineering. The PGM mark is your guarantee of precisely drilled holes for a stable anchor fixing.