Hastings 4.310" Bore Piston Rings File Fit 5/64 x 5/64 x 3/16" Thick Low Tension - Moly M593 The Top Air system fits

The Top Air system fits over the forward two holes and extends down the front of the helmet and just under the top of the visor

CNC-machined 6061-T6 billet aluminum

however its designed to improve the performance of engines that came stock with 2V

15" Bearing Bore

425 in Long

Hastings 4.310" Bore Piston Rings File Fit 5/64 x 5/64 x 3/16" Thick Low Tension - Moly M593 The Top Air system fitsProduct Description: Piston Rings Premium Ductile Moly 4. 310 in Bore File Fit 5 64 x 5 64 x 3 16 in Thick Low Tension Ductile Iron Plasma Moly 8 Cylinder For nearly 100 years, Hastings has earned its reputation as a leader in piston ring technology.