Naraku SKF / FKM Premium C4 Polymide Crank Bearing & Seal Kit - Derbi EBE/EBS & D50B0 50cc. Derbi Senda 50 SM DRD Racing 10-13 Reed Valve Gasket. Derbi Senda 50 R DRD Racing 10-12 Reed Valve Gasket. Derbi Senda 50 SM DRD Racing 10-13 OEM Reed Valve Gasket.