I upgraded my vest to the Chinook a couple years ago but forgot to swap out my whistle off the old one. I was reminded by WDFD on opening day prior to launching. Luckily I was only blocks away from home and not miles away in the boonies. I use this whistle for the NRS vest and it's pretty good for not finding my fly line.
https://www.seattlefabrics.com/34-W...MIo56GhrWSjAMVjR-tBh0UQAiPEAQYAyABEgKEBvD_BwE
https://www.seattlefabrics.com/34-W...MIo56GhrWSjAMVjR-tBh0UQAiPEAQYAyABEgKEBvD_BwE