need a "c" type clamp with an electro hydraulic "screw" approx. 6" jaw and the same depth for mobile car and truck mechanics. Typical use is to dissemble driveshaft "u" joints and re assemble same. A manual "twist handle" type clamp is an arm buster...typical pressures needed under a "ton". The "c" clamp is easily handled to move around the "work" rather trying to manipulate large, heavy driveshafts into a "fixed" press. I would pay up to $3oo. or more for such a unit...the air motor would only require less than 120lbs pressure thru a 3 eigths i.d. line is there some thing out there already ????