All I know is I LOVE my screw jack. So handy when the rod is chucked in the screw gun. Up down with the flip or a switch. I made a special short bolt to fit as well for up close use.
I kinda wish they made a floor jack out of one, at any rate it stay's where you set it unlike a lot of hydraulics. I use it all the time. I may keep it if I sell the truck...
