The K-Tek KS40 (hard rubber) and KS30 (soft rubber) is a pair of normal rubber suspension mounts used on the KSM and KSSM shockmounts. These rubber suspensions are used to replace worn or damaged suspension bands. A spare pair is a must for any professional. We offer both versions in stock, but Vandelay uses the hard rubber version exclusively. The soft rubbery has really good grip. Like, REALLY good!