Product: Package: Instruction: Specification: ÏUse for T-REX 250. ÏNewly designed main gear mount to simplify gear replacement, and improve overall aesthetics of main gear system. ÏNew main drive gear(120T) x 1 ÏMain gear case x 1 ÏBearing 683 x 1(Φ3xΦ7x2mm) ÏOne-way bearing HF0306 x 1(Φ3xΦ6.5x6mm) ÏCross screw x 4(T1.5x4mm) ÏSpace x 1(Φ3xΦ4.8x0.5mm)