1/2 In. wide x 1-1/8 In. diameter hard white PP wheels are mounted to adjustable length stamped steel platform to support and add mobility to heavy refrigerators and appliances. Low profile rollers should be placed on the exterior of appliances to aid in mobility and add 1-1/2 In. to the overall height. 1200 lb. per pair load capacity. Easily adjusts from 16-3/4 In. to 25 In. 4 wheels per axle.