I have one so old it used a wooden jack handle, and has an eccentric wire clamp built into the head and top, so you can stretch barb wire. One of the first ones made in the 40's . Can't imagine anyone holding up a 25 pound jack to fix the top wire! Learned when you grab a Hi-Lift, get a can of penetrating oil also, especially if it has been in the dust in the back of the truck