Originally Posted by MacCool

I just used a plain old hockey puck. This being Minnesota, they're readily available. I ran each puck through a radial arm saw to cut a slot for the pinch weld. I even drilled a 1/2 in hole and glued in a neodymium magnet so that the puck would stay put. Not a huge problem at home, but I always give them to the oil change places so that they can use them when going up on a 4-point lift.