Aluma-Tow, Adjustable Ball Mount, For 2" Square Receivers, An Extruded Aircraft Quality Aluminum Body & Adjustable Section With A 12,000 LB, GTW Towing Rating When Using A 2-5/16" Diameter Hitch Ball, Includes 2 Keyed Alike Locks With 4 Keys, 1-7/8", 2" & 2-5/16" Interchangeable Hitch Balls, A Maximum 6" Drop & 6-3/4" Rise Capability, Adjustable In 1" Increments.