Major height adjustments are made my simply moving the adjustable foot pads inward or outwards; minor adjustments are made at the screw kevel with the provided stabilizing adjusting lever. Designed for use with 5th wheel trailers whose coaches have a king pin height of 39" to 50." Fully assembled with steel tube construction and zinc-plated chain. Lockable for added security. Designed to allow use of padlock to secure Stabilizing Jack to trailer. 5000 lb. maximum load capacity.