Here are all the options parts for the Xray X4
Reference 06305784-O
Brand: XRAY
"SPUR GEAR ""H"" 84T / 48 - ORANGE - 305784-O"
Reference 06308276
Brand: XRAY
XRAY 4S SPRING-SET C=2.7 (2) - 308276
Reference 06301323
Brand: XRAY
FRONT BODY MOUNT SET +1MM HEIGHT - 301323
Reference 06305870-O
Brand: XRAY
OFFSET SPUR GEAR 100T / 64 - ORANGE - 305870-O
Reference 06303128
Brand: XRAY
ALU SHIM 3x6x6.0MM (10) - 303128
Reference 06308027
Brand: XRAY
XLP COMPOSITE 4-HOLE 1.1-1.2MM PISTON (2+2) - 308027
Reference 06305860
Brand: XRAY
OFFSET SPUR GEAR 90T / 64 - 305860
Reference 06305436
Brand: XRAY
HIGH-PERFORMANCE LOW FRICTION KEVLAR DRIVE BELT 3 x 351 MM - 305436
Reference 06302180-H
Brand: XRAY
X4 CFF FRONT LOWER ARM - HARD - RIGHT - 302180-H
Reference 06302181-H
Brand: XRAY
X4 CFF FRONT LOWER ARM - HARD - LEFT - 302181-H
Reference 06303138-K
Brand: XRAY
ALU SHIM 3x7x2.0MM - BLACK (10) - 303138-K
Reference 06303181-M
Brand: XRAY
X4 CFF REAR LOWER ARM - MEDIUM - LEFT - 303181-M