Input DC5V/1A, Working Time UV 2H /White 5H, Interface Type-C USB, Model BW-FUN9, UVC Wavelength 270-280nm, Charging Time 2H, Power 1.5W, Li-Battery Capacity 1200mAh, Effective Height ≦5cm, Working Temperature -20℃~45℃, Product Name UV Sterilamp, Light Source 3pcs UVC & 3pcs White LED, Product Size φ22mmx 190mm.
Basically copy coupon, view price history or create e-mail price alert. What is the best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
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. As you can see I didn’t find any active coupon for this product right now…
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BGBTFEW1, 10%ForNewBW, BGAFF10OFF, BGBWFUN9, BGBWSTRECN, BGAP0706, BGHONEY2110, BG10OFFAFF, BGMAR1004, BGwhielabel, 13f142, BG8ReviTrage, BGOct22LED, BG00c906, BG589b2e
(these coupons are old, so probably won’t work)
Price history and price alert
Price history (for all/most countries) for BlitzWolf BW-FUN9 UV Sterilization Lamp is here. The lowest price was: $7.99.
Price records source(s): 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)).