German polygon wrenches for tightening and loosening without removing the key from the nut. The 5° angle increase allows work in areas where common polygons (30°) or keys (60°) cannot reach. It is the only profile that prevents the key from slipping off the nut, so the risk of accidental injury is practically eliminated. Additionally, tightening is done on the sides of the nut, thus protecting the nut from wear.