I installed mine myself which was very, very easy took me about 20 minutes. I researched and learned that the screw in type that you install just on the inside of the bolt rope lasted for years....so far 3 years for me. I am rough on my sails in pretty high winds and my inexperience with too much flapping. I got them from the MacGregor site and even called and talked to them about it...how many I needed, directions etc. In the picture I included its the one all the way to the left. I can't believe I went through that first year of not having them (or knowing about them) because feeding that bolt rope was an ordeal! Good luck with whatever you decide to do.