Eibach ERS Bump Stop - 1.81" Length (EBS770034)Bump Stop by Eibach Eibach bump stops are made from a micro cellular polyurethane elastomer. They are highly tunable and adjustable, and create a highly progressive, rising rate effect as the springs approach bottoming and possible coil binding. Several Circle Track sanctioning bodies have approved the use of bump stops to help resolve possible control and safety issues relating to abrupt coil bind in softer spring setups. With progressive compression