Skid Steer: All new pattern for skid steer, the Alliance SK-906 is more open and deeper at the shoulders for good traction in soft soil. Solid center for long wear on hard surfaces. The Alliance SK-906 has Open, deep shoulders for traction off-road. Highly abrasionResistant tread compound. Features aRim shield protector and a heavy sidewall. The treadRadius isRelatively flat which is good for wear on hard surfaces.