I would invest on a new machine if i were you. A wise head with that machine is not worth. The single action clamp is terrible. It requires a lot of adjustments, and it leaves crazy marks on the string specially Guts & Multil. The aluminum handle bar for the clamps aren't solid specially by the bolts areas. They worn out on my machine so I retired it a few months back. The company is longer in business so it's pretty hard to find parts for it.