Polyurethane bump stops are designed to eliminate metal to metal contact as your vehicles suspension goes through it's travel cycle. When you lift or lower a vehicle it's always a good idea to be sure you are using the proper bump stops that give you the proper amount of travel. Large competition bump stops are specially deisgned with a reinforced steel mounting plate to withstand teh toughest terrain. Small bullet style bump stops work well for lower control arms and areas that have limited clearance but require maxiumum dampening. Low profile bump stops fit in the tightest of spaces to eliminate metal to metal contact...great for lower vehicles.