Hirobo HI2521091 Collar — 5 x 7 x 18.3 for RC Helicopters  [HI2521091]

Function and Fit

This RC collar, identified by Hirobo model HI2521091, carries the dimensional reference 5 x 7 x 18.3 which is used to ensure correct shaft fit and axial spacing in compact rotorlinkage arrangements. Check that measurement when planning installation.

The part acts as a spacer and alignment aid within rotor linkages or transmission stacks, helping to preserve concentricity between mating parts and to support fine axial adjustment during setup and tuning.

Basic installation guidance: confirm the 5 x 7 x 18.3 size with your model’s shaft or bore, position the collar where the assembly requires spacing, and retain it using your model’s standard fasteners. This product is intended for RC model use only.