Ball bearing SKF 17 x 40 12mm Closed on both sides for Zündapp C 50 Super, Sport, GTS 50, KS Sport Combinette Type 515 510, R Roller CX25 Hai, Hercules wheel hub HS 115 V, K Sprint, MK Super 4, 3 M, 4 RT 159 E, ES, Jet 139 M