Road shock should be absorbed by your suspension, not transferred to your precious cargo. The Lippert Equa-Flex Rubberized Suspension System completes this task with flying colors. Equa-Flex was formulated to absorb road vibrations and protect your cargo. Equa-Flex also helps reduce fore-to-aft trailer movement, otherwise knows as chucking. The rougher the road conditions, the better the system performs. Not only does Equa-Flex virtually eliminate damage to your trailer caused by road shock and vibrations, but it protects your precious cargo as well. Equa-Flex delivers a ride that is as smooth as a torsion axle, but is a fraction of the cost. The patented system allows for the trailer to retain spring axle equalization benefits while offering the smooth ride characteristics of a torsion axle. Independently tested and proven, Equa-Flex tested 7.5 out of a scale of 1-10 whereas the competition scored a 5.0. Equa-Flex showed up to a 60% reduction in road vibration during this evaluation.• Rubberized design intended for tandem-axle trailers• Dramatically reduces fore-to-aft trailer movement• Designed for double-eye leaf springs and weight capacity from 4, 000 to 6, 000 lbs.• Scored 7.5 out of 10 in independent testing, compared to 5.0 by leading competitor• Includes two Equa-Flex sub-units• Each sub-unit comes with pre-installed bronze bushings• Center hanger and other mounting hardware sold separately Delivers a ride as smooth as a torsion axle but at a fraction of the cost Designed for double-eye leaf springs & weight capacity from 4, 000 to 6, 000 lbs. Includes two Equa-Flex sub-units with pre-installed bronze bushings | Lippert Equa-Flex Rubberized Equalizer Tandem Axle Kit, Heavy-Duty, 4,000-6,000 lbs