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. This product is suitable for the Derbi Senda 50 R DRD 2003 (EBE050) [VTHSDR1GB].