| Suitable for T-REX 550E, 550L RC Helicopter Electric Series Not for Use On: 550X or 550 with 600 Size Boom Bearing Replacement Torque Tube Bearing Holder - H60124 (MR148ZZ) 8z14x4mm - H60002 | Specifications Torque Tube x 1 Bearing MR148ZZ (8x14x4mm) x 1 |