DESC: This innovative jack makes it easy and safe to change tires on tandem-axle trailers. Its unique rocker shape allows you to simply drive the trailer onto the jack and elevate the tire for changing. There's no more hassling with awkward jacks or wooden blocks. Made of heavy-duty cast aluminum, it's lightweight (less than 9 lbs.) yet extremely durable. It also doubles as a wheel chock when used in the reversed position. Also great for leveling campers and RVs when used in tandem under the front or rear tires. Trailer Accessories