Self locking ratchet pawl prevents premature release and allows positive locking action.>With 5 size:         

A.2"Height capacity:1-1/2"to3-1/8"(40-80mm).                                    B.3"Height,capacity:2-1/8"to5"(53-125mm).                                C.3"Height,capacity:2-1/8"to7"(53-175mm).                               D.3.5"Height,capacity:2-1/8"to5"(53-125mm).                                                               

 E.4"Height,capacity:2-3/8"to7"(60-175mm).                                  F.6"Height,capacity:2-3/8"to7"(60-175mm).