The lock screw dissolves repeatedly over time, so that the fixing screw can turn (screw to fix the cable diameter) and thereby failed to fulfill its its intended task. Already have favorable strippers used, where that was not the case. Too bad, because actually I swear on KNIPEX pliers. However, the cutting should be good. Anyway, I can not have any wear after about 25 rooms rewiring notice. But I also make sure they do not abuse the side cutter)