A brake pad includes a support plate which is embodied as a cast piece as well as a friction lining that is attached therein. 3H2O solids in a reactor generates reaction heat in the reactor, and where air is used as a coolant in a cooling jacket around the outside of the reactor to produce heated air, which heated air is combusted with natural gas to provide combusted exhaust gas which can be used as a heating agent. The radiating element is fed electro-magnetically by a parallel planar feed element connected to the antenna port and located near the radiating element, between it and the ground plane. The disclosed low-output impedance RF driver circuits eliminate the need for a matching circuit for interfacing with the inherent impedance variations associated with plasma. The narrowband optical reflecting element includes a glass element having a Bragg grating arranged therein.