I LOVE mine!!!
A bracket is mounted on the spring plate using the existing U bolt for securement, another bracket is bolted to the front spring hanger via new drilled holes. A bar goes between both brackets, thus creating less wheel hop and axle/spring 'twist'.
Mine have been on and off and on and off because of lifts, or axle swaps, etc....and i notice a huge difference every time i put them back on. When they are off, I can't even tell if i'm spinning the tires around a corner..they spin so easy. After the install.....sure there's some hop still...but not much. The only hop that's there is because i'm a manual and the torque i'm putting to the rear.