That is exactly my main issue with these.
They max raise your car by 38 cm.
Those from CJ-auto can be used on all 4 wheels.
If you use them on 4 wheels, then put axle stands under all 4 corners (needed if you need to remove the wheels).
The suspension will give in also, resulting your wheels will not be much off the ground any more.
38cm is also tight if you need to weld, drill, etc
I would ideally have the car up for about 50 cm (max 60 cm).
50 cm is also the max height on most jacks (although that's not under the wheels - I often tend to use a 10cm wooden block under the sill to get the extra lift)