We tested three different pieces of equipment. All do the same job, but they work a little differently from each other. The bottom link is a solid third link, which we used for our baseline. The middle piece is from Allstar Performance. It has a 1,600-pound spring and a canister to control the proload of the internal spring. The top bar is from Coleman Racing Products. It has a 1,000-pound spring and is very simple to use.