Rear wheel cylinder, as used on early 850, Mk2 and Mk3 classic Minis up to '77, Mk2 Cooper S, '79-on 998 Minis. Best replaced in pairs. OEM manufacurer; sold each. Ref: GWC1102, LW11396, GWC1919.
See GRK2014 for repair kit. See GWC1102E for aftermarket version.