Just for clarification, the device you're referring to is often called a " boom pig tail" and is solely used when the sail is flaked and stored on the boom. A topping lift supports the boom during boat's use, sailing or motoring, but generally if the sail is up. It is never advisable to clip the boom to the pig tail if the mainsail is deployed and especially if you are actually sailing. Think about it. If you have a boom kicker, or rigid vang, there is no need for a pig tail. I clipped mine off long ago and got rid of the topping lift as soon as I installed my garhaurer rigid vang.