Side Rails are 3-1/2" High. Welded construction for superior strength; no assembly required. Little or no maintenance. Made with a steel underframe for greater weight capacity. Completely powder coated plus an aluminum platform and ramp that is corrosion resistant. Optional hitch height adapter available for vehicles with hitch clearance less than 12". Optional Class II Hitch Adapter for 1-1/4" Hitch Receiver. Platform Dimensions 51" L x 32" W x 3-1/2" H. Inside Platform Dimensions: 48" L x 30" W x 2-3/8" H. Ramp Dimensions: 48" L x 25-3/4" W. Class III and IV Load Capacity: 350 lbs. Class II Load Capacity: 350 lbs. - refer to vehicle owner's manual. Surface: Slip resistant traction tape. Compatibility: Class II, III or IV Hitch.