I have the six inch version of that vise. It works just like normal, however it wont open as far as a standard machinist vise. The jaws will close .5" when powered. With my vise clamping force of the jaws is adjustable, by air pressure, up to 6000 lbs.
To power the vise you need air pressure, air/hydraulic cylinder and a pedal. I have the vise, stand and air/hydraulic cylinder. Hopefully Ill have time to get it running latter this year.