Rear coil spring isolators manufactured by Energy Suspension are made with superior HYPER-FLEX™ polyurethane material. The material lasts 3-10 times longer than rubber isolators and does not require frequent replacing. Coil spring isolators can be assembled to the chassis the same way as OEM. isolators. Energy Suspension Polyurethane coil spring Isolator lasts longer compared to original rubber inserts. It also provides a strong and quiet base for the springs. Coil springs help in supporting the vehicle’s weight and when riding on a bump or a turn it compresses the suspension travel. Annoying metallic squeaking noise is caused when rubber isolators get damaged. It mainly happens due to its placement. Hyperflex Polyurethane is used in coil spring isolators, which makes it durable and long-lasting compared to rubber isolators. It absorbs the beating that the springs produce and remains unaffected by weather, grime, road salt, and rubber degrading elements. It comes in pairs for complete replacement.