Rough roads ahead? Take 'em on with Equa-Flex, a patented rubberized equalizer that absorbs road shock instead of transferring it to RV and cargo. Equa-Flex delivers a ride that is as smooth as a torsion axle, but at a fraction of the cost. Our patented system allows the trailer to retain spring axle equalization benefits and provides the smooth ride of a torsion axle. With Equa-Flex, you're getting the best of both worlds.This kit is for tandem-axle trailers with double-eye leaf springs and weight capacity from 4,000 to 6,000 lbs. The center and top bolt holes have a diameter of 9/16". Bronze bushings come pre-installed. Center hanger and other mounting hardware sold separately.Whether you're on the road or on the water, Lippert supplies a broad array of premium RV, towing, and marine products designed to enhance all of your recreational pursuits. Our team is committed to always thinking about your next journey — pushing the possibilities of our products and services, all to better your time spent outdoors, whenever, wherever, for years to come.