Hyper-Flex Coil Spring Isolator Set (4.6111R) by Energy Suspension. Red. This is a set of cushioning spring pads designed to be used either on top of or below a rear coil spring. Use both pads to insulate the top and bottoms of one spring, or spread them out between left and right sides if you only need coverage on the spring bottoms. Resilient polyurethane construction offers greater resistance to deterioration from road grime, oil leaks, and salt slush without drying out or crumbling the way rubber mounts can. Replacement of existing factory springs, shock absorbers, or struts is not needed.