The Fox 40 Micro is available for purchase through my Amazon storefront (I earn a small commission) amzn.to/3XpEfxT How to blow into a whistle: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-q2gl87GGb6Y.html See this whistle compared with all other Fox 40 whistles: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-abboYzpIJto.html
636 can be overblown meaning that if you use full force it will sound awkward and bad. Micro sounds the same no matter what so therefore I prefer the Micro.
