Abstract: A wheel assembly is disclosed for attaching to or integrally forming with an object, such as a plastic-molded tub or cooler. The wheel assembly includes an elongated axle terminating at each end with a wheel. A plurality of rails are each adapted for fixing with the bottom surface of the object. Each rail has a plurality of axle notches adapted to selectively receive the axle. A pair of arms are each fixed at a first end thereof with the axle proximate the wheels, each arm being fixed at a second end thereof to a pivot rod that is selectively and pivotally engageable with one of the axle notches. At least one axle lock is adapted to be fixed with a side surface of the object. As such, the axle may be pivoted between the inside position, wherein the object may be rolled along the ground surface on the wheels, to the outside position, whereby the axle is engaged with each axle lock and the wheels are lifted above the ground surface to prevent the object from rolling.