Tail Drive Gear Assembly H50043Instruction: Use for T-REX 500Specification:Shaft x 1(Φ4xΦ4.8x42mm)Tail drive gear(31T) x 1(Φ4.2xΦ19.8x9mm)Metal pulley cover x 1(Φ4.4xΦ14.5x4.5mm)Drive pulley(19T) x 1(Φ4.4xΦ6xΦ11.75x4.15mm)Bearing 684ZZ x 2(Φ4xΦ9x4mm)