Aluminum Stabilizer Jacks by Ultra Fab 48-979003Aluminum stabilizer jacks adjust from 11" to 17" above ground. Smooth, effortless adjustment assured by rolled threads.  Available in Aluminum stabilizer jacks 2 or Aluminum stabilizer jacks 4 pack. Aluminum stacker jacks are perfect for tent campers and smaller trailers. Handy 2 pack allows for added stability and support. Specifications for the Ultra Fab Stack Jacks:Super tough, die cast aluminum constructionExtends from 11 inches to a full 17 inchesPerfect for trailer stabilizationEasy to set up and adjustJacks come complete with fully adjustable handlesStackable units take up minimal storage spaceLifetime manufacturers warrantyNote: For Stabilizing Only. NOT for Lifting