Stability The support stands to help a little bit in the stability of the trailer.Great for providing support and stablize to RV slide outs when extended Adjustable Design The stabilizer jacks support 5,000 lbs.Each and adjust from 20" -42" H. The 5" dia Built to Last Constructed of heavy duty steel, Each camper slide out stabilizer is finished with a zinc powder-coating for longevity and resistance to rust and corrosion Product Specifications Package includes 2 PCS camper slide out stabilizers travel trailer leveling jacks to add to your camper accessories Suggest It is suggested to use concrete blocks or wooden leveling blocks for campers to stabilize the RV slide out jacks on an even surface.