Classic Minis have only used two sizes of CV joints since 1961, one being small and one large. This one is the small one found on 1961-on Classic Minis with front drum brakes, 997, and 998 Cooper models. Sold as a kit, with rubber boot and grease pack included. Ref: GCV1105.
Very early Minis had CVs with 18 splines, and the current ones will not fit.