7500lbs RV Stabilizing and Leveling Scissor Jacks 24 Inch Set of 2 Features: These 2 scissor jacks can be bolted or welded to the frame of your trailer or RV. Worm-gear mechanisms are designed for non-slip. Oversize footplates help to eliminate sinking and tilting, keep your RV level and stable. Safe Operation: 1. If your RV is on uneven ground, please place bricks or other stable objects beneath the wheels of your RV/trailer before using the RV jacks to prevent it from rolling away. 2. Raise or lower the stabilizer leveling scissor jacks by the crank handle or power drill (not included) until the jack is closely wedged with the RV's base.