Lely Discovery Tire with Steel Wheel & Poly Hub. This a replacement tire for the Lely Discovery alley scraper. These tires are the exact size as original ones, so there is no need to change route programming. They are a solid rubber traction tire with a steel wheel and poly hub. Hub can be replaced if need be without having to trash tire. Have been using these on our machines for 2 years now, they work. We gain in performace and less battery drain vs. original tires, plus they don't break.. They are built to last and do last. Ours already have 2 years on them and are basically as they were from the day we installed them. You are buying a set of 2 tires.