The OTR NDX 26X12.00-16 Airless Tire Assembly is a complete bolt-on airless tire and wheel assembly for commercial zero-turn, riding, and stand-on mowers. Engineered to eliminate flat tire downtime, the NDX Neverdown system uses a patent-pending multi-layer construction with a Grass Master tread pattern. This assembly fits machines requiring a 4x4 bolt pattern with a -1.00" offset. No air required -- ever.