Instruction: 6061-T6 Aluminum alloy material and CNC processed。 Use for T-REX 500E / 500ESP / 500E PRO / 500EFL PRO. Dual radial bearing with thrust bearing design to dramatically increase rudder precision and gyro locking action. Specification: Metal tail rotor holder x 2 Bearing MR84ZZ x 4(Φ4xΦ8x3mm) Tail rotor hub x 1(Φ8.8x40.4mm) Tail Rotor Holder Washerx 2(Φ6xΦ8x0.3mm) Thrust bearing x 2(Φ3xΦ8x3.5mm) Washer x 2(Φ2xΦ6x0.6mm) Socket collar screw x 2(M2x6mm) M4 set screw x 1(M4x3mm) Socket button head collar screw x 2(M3x12mm) Weight:20.5g