I am going to do some pretty extensive tests on these things once I get my pool good and clean. I bought the small 12 lb and the large 20lb release. I have read a little about these and some people seem to think they are a gimmick. I plan on attaching the lure I put them on to 10 lbs of weights and dragging them across the bottom to simulate a large fish, and see if they will pull free. Then I will be testing to make sure the release when they are supposed to (before line breaks) buy securing the lure to something under water. I will finish this review once I have done these.