The 3x7x3 F683ZZ Halo series of bearings are a high quality steel/chrome flanged 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: 3mm (Inner) x 7mm (Outer) x 3mm (Width)
STANDARD: 0.11811" (Inner) x 0.27559" (Outer) x 0.11811" (Width)