I had to use both - a six ton bottle jack and the screw jack from my truck. When the tire was flat, the bottle jack didn't have enough travel to get the RV high enough to put the new tire on. My truck jack isn't rated for the weight of the RV. I have to lift the RV as far as I can with the bottle jack. Slide the screw jack under to hold it in place while I unscrew the adjuster on the bottle jack. I reverse the process to let it down.