Sparco SPX carbon fiber shells with leather and alcantara covers and articulating backs. These are extremely light (28 lbs.) and comfortable seats for street and track use. I have had GMG Racing attach seat bases, sliders, and sub strap mounts. The backs have pass throughs for harnesses. I will throw in a set of six-points Schroth harnesses that a good for the rest of this year. All told close to $9,000 invested.