17x30x7 Rubber bearing (6903-2RS) by Avid Racing Concepts is the standard bearing for the HPI Baja 5B. Check your manual for the correct size for your vehicle if you are not certain.
Bearing Dimensions
METRIC: 17mm (Inner) x 30mm (Outer) x 7mm (Width)
STANDARD: 0.66929" (Inner) x 1.1811" (Outer) x 0.27559" (Width)