Bessey PZ4.012 Rapid Action Clamp with No Twist Clamping Action & 12" Capacity, x 4" Throat Depth, Red/Black 1,320 lb. clamping force, cold drawn German steel rails Sliding T style handle fro high force clamping Enclosed double action threaded spindle applies force with out twisting Serrated German steel rails for positive no slip clamping Exclusive patented Bessey hardened set screw engages with rail serrations for positive no slip clamping