ProX pistons are precision machined on the latest, state of the art CNC equipment. The same low-expansion, low-friction piston alloy is used as is used for all major Japanese engine manufacturers. ProX Piston Kits are a first class solution to replace the original piston in your Motorcycle, Scooter, Moped, ATV, Personal Watercraft, etc. The latest cylinders are plated by a Nicasil plating. Therefore we offer a wide range of ProX pistons in standard size, as well as in A, B, C, D+ oversizes.