HPI is the one-way bearing for the Nitro Star 21BB engine. Also fits the Roto Start for the Savage. This One-Way Bearing allows the recoil starter to grab the crankshaft to start the engine and spin freely in the opposite direction.

HPI 3mm x 6mm x 2.5mm Ball Bearings used on many Cars

HPI 5x13x4mm Ball Bearings

HPI 12x18x4mm Ball Bearings for the R40 touring car. These bearings are used in the rear bulkhead set.

HPI 4 x 9mm Thrust Bearing for the Proceed.

HPI 5 x 10mm Thrust Bearing for the Proceed.

HPI bearing set for the MT truck, RS4 Pro, RS4 Sport, and RS4 electric minis (not the nitros).

HPI Racing complete bearing set for E10 Touring/Drift cars.

HPI stock eccentric bushing set for Hellfire.  These bushings push into the aluminum suspension mounts and allow you to adjust the models front inboard angle, rear toe angle and rear anti-squat.

HPI 5x10x3mm brass washers for use on the Savage 21.

HPI Two Bearing 3x6x2.5mm Flanged RS4 Pro 4.  For general use.