Hirobo HI2521057 4 x 6 x 3 Collar Spacer for RC Helicopters  [HI2521057]

Compact 4 x 6 x 3 collar summary

This Hirobo HI2521057 collar matches the 4 x 6 x 3 sizing shown in the product name and functions as a small spacer component where that dimension is required. The wording here stays within the provided naming and the part's spacer and alignment role without adding extra specifications.

To fit the collar on compatible shafts or linkages that accept a 4 x 6 x 3 collar, slide the part into place, check axial clearance, and secure any model-specific retaining elements. If your assembly uses a set screw or retaining clip, use that to prevent axial or rotational movement; otherwise confirm fit with a trial assembly and minimal movement checks.

Used primarily for spacing and alignment, this collar influences stack height and endplay rather than providing a direct performance upgrade. Make adjustments incrementally and inspect for binding or excess free play during control surface and rotor checks.