The Rupes backing pad is an essential element of the BigFoot system. It is made of polyurethane foam that is particularly resistant to mechanical stress. In combination with BigFoot polishing foams, the backing plate creates a system that significantly reduces vibration. The holes in the backing plate create an air flow that dissipates heat and keeps the work surface at an acceptable temperature. The material used in the fastening system creates an effective anchoring system, giving the foam exceptional stability while the tool is in use. Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.