Cross-Section or Diameter: 275. Aspect Ratio or Width: 55. The Open Country M/T from Toyo Tires is the biggest, the baddest and the most aggressive off-road tire to hit the market. Not for the faint-of-heart or the casual truck owner, these tires are built for the workhorse rigs and off-road machines. Toyo squeezed so much awesome into one set of tires it would take pages to describe all the benefits of, so here is the real important stuff. Every Open Country M/T is constructed of high turn-up 3-ply polyester, which provides excellent durability, impact resistance and handling. These tires are designed with the industries most aggressive tread designs with the recognizable hook-shaped blocks. This tread design contributes to the M/T's superior off-road traction while still maintaining excellent on-road stability. The tread design is complimented by equally aggressive scalloped shoulder blocks that extend over the shoulder to further improve off-road traction, enhance your vehicle's grip in deep mud, snow, sand and whatever else you decide to power through If getting stuck just isn't an option, Toyo has you covered with the Open Country M/T's, the industry standard in off-road tires.