Medium choc: Zico Chocs feature high-ternsile strength aluminum construction, large rear opening hand grip, and double row of rugged teeth to grip almost any firm surface. Recommended for smaller service vehicles such as pickup trucks, speciality trailers, etc. WARNING: undersized chocs may fail to restrain vehicle . The vehicle may either roll over or crush an undersized choc, possibly resulting in bodily injury or property damage. The AC-1 is: 6-1/2" high, 6" Wide and 11-3.4" long. It weighs 3.7 pounds. Please see our QCH-1 for a horizontal choc holder or the QCH-11 for a vertical choc holder. Model QCH-SL Safety latch may be added to any ZICO horizontal choc holder.