Aimed at the professional heavy user, these bits are made to last significantly longer, require less pressure and reduce working time. Hence they offer reduced costs to the full time user. Wiha have coated the tips with thousands of microscopic diamond particles. The fine particles grip in the screw head helping to prevent slippage. The set contains Wiha's top of the range CentroFix bit holder, 1 x 5.5mm slotted bit, 1 x each Pz1 and Ph1, 3 x Ph2 and 4 x Pz2, and 1 x each Ph3 and Pz3. The bit holder is impact resistant, glass-fibre reinforced polyamide, tough and reliable; it will keep the bits safely stored until required.