I've had 50% success rate, but the two that have worked have done so for about a year now, and have been a game-changer in deep woods (Southeast Alaska rain forest) or low visibility (Southeast Alaska on most days) or for people with visual impairments (yay accessibility!). Like others, I had them pop off when they hit a tree, but I've used Marine Fast Cure glue (Loctite) and they are still there. They can SLAM into a tree and the squeaker stays on. Boaters assure me I'll have a heck of a time getting them off one day. They could be louder, but I think there is a happy medium between reeling you in when you are close, and letting the whole course know where your disc is. They ARE muffled if under the disc and in deep duff, so keep an eye on where your disc is going. It would be nice if further editions could have a variable squeak, so that if multiple people are using them you can differentiate.