A choice of 12mm or 14mm diameter one-way bearing for all 'F series' HPI Savage nitro engines.
21BB - 12mm
S25 - 12mm
F4.1 - 12mm
F5.9 - 14mm
F3.5 - 12mm (version 1) or 14mm (version 2)
F4.6 - 12mm (version 1) or 14mm (version 2)
Overall Length: 12mm, Hex Width: 12mm or 14mm, Inner (shaft) Diameter: 6mm.
Not for K Series engines.