Factory calibrated to +/-3% and our new mechanism ensures that the accuracy is retained for longer Every wrench is supplied with a calibration certificate to satisfy the requirements of ISO 9000:2000 Ergonomic new handle with a high proportion of soft-feel, high grip material Handle material and lens resist all chemicals in common automotive, industrial and aviation use Secure push/pull locking mechanism is quick and intuitive to use and prevents accidental adjustment, Weight: 4.7840310854 Pounds, Manufacturer: Norbar