I've lost a few of them and have always replaced mineEverything.
Tone. Volume. Ergonomics. Flexibility.
Very often get a "f*ING hell ref" when players too close and has made its way into observation reports commenting on use and tone of whistle (positive) something I know I couldbt have done with any of the other whistles (fox40, sonik blast, acme thunderer all predecessors to the Valkeen.)
If anything happened to it I would pay the money to replace it in a heartbeat
More recently, I bought a knock-off Valkeen as well which I keep forgetting to put to the test. Probably, it will be exactly the same
Surely, it's just a bit of plastic with a fairly precise shape. Otherwise though, the Valkeen is on a different level. That and the finger-grip changed my life