prevents insert tools being swappedthe system is locked in place on the head of the torque wrench by means of a safety screwonce the protection system has been fitted, it is possible to attach an insert tool but not to remove it because the QuickRelease unlock button itself is lockedafter the safety screw has been removed, the torque wrench reverts to being a standard, versatile toolthe safety screw can be fitted and removed using a TORX® screwdriver with a central bore in the tip (No 4656, size T20, Code 46 56 30 20) or a bit screwdriver insert with a central bore in the tip (No 1442, size T20, Code 08 16 00 20)