Convoy M21B SST40 Flashlight (Banggood, Aliexpress: Required battery quantity 1 pcs, Mode memory Yes, LED Luminus SST40 with DTP copper plate, Weight 120g, Battery included No, Reverse polarity protection Yes, Tailstand Yes, Required battery type 21700 or 18650 lithium (battery tube inner diameter 21.5mm), Material Aluminum Alloy, Lens type ar-coated glass, Reflector Smooth, Diameter (Head/Body) 35.7 / 27.1mm, Max current output 6000mAh 2300lumens, Driver 4 modes 0.1%-3%-30%-100%, Length 141.5mm, Low voltage warning Yes (the best price with coupon)).
Basically copy coupon, view price history or create e-mail price alert. Let’s see what best price is ATM.
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($20.90): BGM12B
2. ($21.59): AC19
3. ($21.59): BG13TH
4. ($23.75): BGTORCH
paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Price history and price alert
Here is price history (for all/most countries) for Convoy M21B SST40 Flashlight. The lowest price was: $18.89.
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)).