This Boxster s 3.2-3.4l je piston set enlarges the bore while maintaining proper quench, which allows for faster burn and better thermal efficiency, leading to better gas mileage, lower potential for detonation, and more power by retaining the factory inverted dome piston shape, mirroring the pent-roof four-valve combustion chamber! These pistons are as strong as the forged pistons found on s engines, but use a lightweight forged side relief design for improved strength while being lighter than the factory pistons. Includes rings, pins, & clips.