Here are all the options parts for the Xray X4
Reference 06305436
Brand: XRAY
HIGH-PERFORMANCE LOW FRICTION KEVLAR DRIVE BELT 3 x 351 MM - 305436
Reference 06302133-S
Brand: XRAY
X4 CFF CARBON-FIBER FUSION UPPER ARM - SOFT - FR/RL - 302133-S
Reference 06302240-H
Brand: XRAY
X4 COMPOSITE HUB - HARD - 302240-H
Reference 06305781
Brand: XRAY
OFFSET SPUR GEAR 81T / 48 - HARD - 305781
Reference 06305862
Brand: XRAY
OFFSET SPUR GEAR 92T / 64 - 305862
Reference 06308027
Brand: XRAY
XLP COMPOSITE 4-HOLE 1.1-1.2MM PISTON (2+2) - 308027
Reference 06308328-K
Brand: XRAY
XLP ALU CAP FOR SHOCK BODY - BLACK (2) - 308328-K
Reference 06305395
Brand: XRAY
ECS BB SC DRIVE SHAFT PIN 2 x 8.4 (2) - 305395
Reference 06302640-T
Brand: XRAY
X4 ADJUSTABLE CAMBER SCREW 14MM M4 L/R TITANIUM (2) - 302640-T
Reference 06305245
Brand: XRAY
ECS BB DRIVE SHAFT ADAPTER - HUDY SPRING STEEL™ (2) - 305245
Reference 06930154
Brand: XRAY
BALL-BEARING 1.5x4x2 STEEL SEALED - OIL (4) - 930154
Reference 06308177
Brand: XRAY
XLP SPRING-SET C=2.7 (2) - 308177