Factory accuracy: ± 2% except: - R.306-25D - K306-600D - K306-1000D (± 4%). - R.304DA (± 6%). Reliability of mechanism: 50 000 cycles (wrenches up to 200 N.m). Use possible with accessories: - End fitting: 9 x 12 or 14 x 18 mm. - Diameter: 30 mm. One-way wrenches usable for unscrewing by reversing the bits. Numbered wrenches supplied with ISO 6789 calibration certificate. Supplied in a plastic box with ratchet and hinged handle (except Ref R.306A25 - R.301A - K.306A600 - K.306A1000).