This is the HPI 190mm wide/255mm wheelbase

Diameter: The o-ring is 20mm in diameter and 1

16 Tooth Pinion Gear

Polished spokes with chrome finish

Compression mount

HPI Racing 86866 Drive Gear 55T Diff Case Set Sintered Metal Firestorm RTR Power & Dcc Supplies This is the HPI 190mmHPI Racing 86866 Drive Gear 55T Diff Case Set Sintered Metal Firestorm RTR This is a genuine HPI Racing 55 tooth drive gear and diff case set in sintered metal for the Firestorm RTR. The sintered metal construction gives the drive gear serious durability for hard nitro running. If your gear or diff case has worn from long use, this factory set restores solid, dependable drivetrain performance with a direct installation. Genuine HPI Racing replacement