Customizable keychain - pendant - whistle

This design is a remix of many previous creations I've made, unified into a single piece. I am providing a base 3D model that can be freely modified. 

I recommend adding negative 1mm deep engravings instead of reliefs to maintain the whistle's functionality and ensure robustness. Printing in PETG or even ABS is advised, as PLA pieces tend to be very fragile. I am unsure which resin would be best for printing since I don't have one. 

Additionally, I'll include some examples of keychains I've made for my friends.