Product Details + Urethane Coil Over Spring Rubber Features molded in handle Available in two thicknesses: Standard or Extra thick to fit our Integra MX Springs Standard is 3/4″ Tall Extra is 1-1/4″ Tall Made from K-Prene Urethane Double Grooved Available in (3) different durometers Yellow: Soft, Orange: Medium, Red: Hard Measured from Groove to Groove