Use coupon and get Survival Whistle Colorful for $5.78 (from Banggood). Just check coupons out (with price alert and history). What is best price?
Latest price update (UTC time):
High-frequency 150dB volume, It’s the same as FURA whistle
Banggood ($5.78)
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood. Low/high price? Current price is the lowest in history (according to CouponsFromChina database)!
Link: Banggood product page
Price: $5.78
This is the best price ever noted in my database!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Do you need price history chart (for all/most countries) for Survival Whistle Colorful? There we go.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).