$6.20 – Waterproof 80L Rucksack Cover (Banggood, Aliexpress: Waterproof 35-80L Rucksack Cover Backpack Bag Cover Rain Cover Perfect for Hiking Camping Traveling Cycling Outdoor Acclivities – 2XL (the best price with coupon)).
I have just checked coupons. The lowest price I could get is $6.2 for Waterproof 80L Rucksack Cover (in Banggood). Go down and check coupons out. Remember to check price history if it is available. You probably want to know what is the best price?
Latest coupon and price update (UTC):
Banggood ($6.20)
Banggood warehouse is located in China. Coupons for Waterproof 80L Rucksack Cover? Nope, there’re no coupons in Banggood. Price? I have never seen better price than the current one in CouponsFromChina database, so it’s the best!
Link: Banggood product page
Price: $6.2
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/feV
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.
Price history and price alert
Here is price history (for all/most countries) for Waterproof 80L Rucksack Cover. The lowest price was: $6.2.
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)).