Atwood RoboFoot Retractable Leg Assembly, 2 1/4" Tube, 3.5KFits jacks with 2 1 4" diameter outer tube. Get an additional 6" of height for your trailer jack. No blocks or bricks needed. Foot automatically flips up and out of the way for simple storage and travel. Footplate is 4" x 5". Features: Easy to use trailer jack foot provides additional height for proper clearance Eliminates the need for blocks or bricks when positioning your trailer Minimizes amount of cranking required to set up jack Makes it easy to