The 6" cuff Aireator SL is a new, even lighter weight Aireator. If you're not super technical with your socks, don't sweat it. These socks have an amazing feel that you'll want to wear riding and pair casually. The feel is described like a slightly "smoother" Aireator. The Aireator was the original DeFeet sock. Over the years it has undergone a variety of improvements and variations. The SL is a variation that for many will feel like an improvement.