I just installed a soiid boom vang from Garhauer on my 88 cat 30, and couldn't be more pleased. It's a far better piece of hardware than I expected to get for the price, and it works slick. Ive always had a soft vang on other boats, and was about to buy one, but decided to give a hard vang a try. I will never go back.The Garhauer is much more powerfull, and much more effective shaping the sail on all points.The topping lift can be thrown away, which is a big bonus. Installation involves only drilling and tapping for ten machine bolts, or pop rivets, and go sailing. Very nice. Good sailing Ron B