Wilwood's Combination Parking Brake (CPB) Hydra-Mechanical Caliper uses hydraulic pressure for stopping and a mechanical locking mechanism for a parking brake. This redesigned unit provides new options for drum brake conversions and disc upgrades on rear axles that are not conducive to internal shoe systems.Match this caliper with the correctly proportionate rotor diameter, provides balanced bias and brake performance for use in conjunction with front wheel brake upgrades.Designed with a single piston and floating mount to attach to a fixed radial mount bracket. Using a floating mount the caliper can maintain perfect alignment when the cable actuated mechanical parking brake lock is engaged and then released. The floating mount will also keep the caliper and disc alignment correct which will prevent excessive pad knock-back on c-clip rear axles with measurable side play. This design also means that when pad wear takes affect the caliper will still be centered over the disc.Having a Rad