Product: Instruction: Specification: ●Suitable for T-REX 550E / 600E PRO / 600EFL PRO. ●6061-T6 Aluminum alloy material and CNC processed. ●Metal Main rotor holder x 2●MR148ZZ Bearing x 4(Φ8xΦ14x4mm)●Socket collar screw x 2(M4x25mm)●M4 nut x 2