Hirobo 7 x 8 x 4 HI2521146 Retention Collar for RC Heli  [HI2521146]

Tail and linkage collar for RC rotorcraft

This Hirobo HI2521146 collar, sized 7 x 8 x 4, functions as a compact axial clamp to secure shafts, linkages, and sliding elements inside RC helicopters and similar models.

Intended as a simple replacement item, the component focuses on positional retention rather than bearing heavy radial loads. It prevents movement of cyclic linkages, tail shafts, and intermediate studs caused by vibration or during setup. Always confirm the 7 x 8 x 4 sizing is compatible with your shaft and bore before installing.

Installation advice: wipe mating surfaces clean of burrs and grit, position the collar and check it seats correctly while allowing required rotation, inspect periodically for any sign of wear, and swap it out if the fit degrades. This item serves as a maintenance spare for RC helicopter tuning.