These jacks are designed to stabilize a portion of your trailet's weight,not to support the full GVWR of your trailer. Do not use these jacks to lift your trailer or RV.Doing so will exceed the capacity of the jacks. This leveling scissor jack with a6500-lb capacity will keep your Rv level and stable.It adjusts from 4to 24 inches as your situation requires,and the bow-tie base steadies the jack on soft surfaces.