I never leave home without at least 3 jacks.
One scissors jack, one two ton bottle jack and one twelve ton bottle jack..
and a 12" x12" piece of 3/4" plywood along with three 12" long wheel chocks made out of 4"x4".
The scissors jack came off an old truck I had back in the 1960's and the two bottle jacks came from K-Mart sometime back in the 1970's.
Both of the bottle jacks combined cost me less than $20 at that time.
I have never had either of the bottle jacks fail me.. nor have they have ever leaked.
The reason for three jacks is because you never know what type of terrain you will find your self on when having to change a flat tire..
If the 12 ton will not fit under the frame or axle, I simply use the scissors jack or the 2 ton bottle jack to lift the wheel high enough so the 12 ton will fit under..
Also if the 12 ton will not lift the wheel high enough to slip off/on the tire, then I have the extra chock to elevate the jack another 4"..
So far... knock on wood, I have never had a problem that this combination could not handle..
But as we all know... tomorrow is another day with a new set of problems to plague us..