Here are all the options parts for the Xray NT1 2018 and olders
Reference 06335553
Brand: XRAY
COMPOSITE 2-SPEED GEAR 53T (2nd) - V3 - 335553
Reference 06335555
Brand: XRAY
COMPOSITE 2-SPEED GEAR 55T (2nd) - V3 - 335555
Reference 06335557
Brand: XRAY
COMPOSITE 2-SPEED GEAR 57T (1st) - 335557
Reference 06335560
Brand: XRAY
COMPOSITE 2-SPEED GEAR 60T (1st) - 335560
Reference 06335570
Brand: XRAY
ADAPTER 2-SPEED - 335570
Reference 06335657
Brand: XRAY
GRAPHITE 2-SPEED GEAR 57T (1st) - 335657
Reference 06335658
Brand: XRAY
GRAPHITE 2-SPEED GEAR 58T (1st) - 335658
Reference 06335790
Brand: XRAY
COMPOSITE BALL-BEARING BUSHING FOR MIDDLE SHAFT (2) - 335790
Reference 06335801-O
Brand: XRAY
LOW FRICTION COMPOSITE BELT PULLEY SET - GRAPHITE - 335801-O
Reference 06335810-O
Brand: XRAY
LOW FRICTION COMPOSITE BELT PULLEY 20T - 2-SPEED-CENTER - GRAPHITE-33
Reference 06335828-O
Brand: XRAY
LOW FRICTION COMPOSITE BELT PULLEY 18T - 2-SPEED-SIDE - GRAPHITE - 33
Reference 06335859-O
Brand: XRAY
LOW FRICTION COMPOSITE BELT PULLEY 19T - MID-CENTER - GRAPHITE - 3358