Adjustable Height Floor Locks. This one of a kind floor lock includes an adjustable height foot pad that will work on carts with different caster heights. The adjustable height feature provides uniform locking and safety unlocking force for better ergonomic operation. This feature also keeps the floor lock working properly as spring and pads wear over time. Height is adjustable by turning the bottom pad. This unit has a bright zinc plated finish with heavy-duty cast steel construction. The bottom pad includes suction-cups for extra grip. Specs: extended height 5 1/2" to 7 3/4"; retracted height 4 1/2" to 6 3/4" used with caster size 4" - 6".