The Halo series of bearings are a high quality steel/chrome bearing with metal shields. These bearings have been tested and proven by many racers. Please check your manual to see if these are bearings you need to use.
METRIC: 2mm (Inner) x 5mm (Outer) x 2.3mm (Width)
STANDARD: 0.07874" (Inner) x 0.19685" (Outer) x 0.09055" (Width)