Aliexpress
Click here… to search for Xiaomi Ultra-thin 10000mAh Power Bank 2 Black on Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Price history and price alert
Here is price history (for all/most countries) for Xiaomi Ultra-thin 10000mAh Power Bank 2 Black.
Price records source(s): Gearbest
Click on image to enlarge. 
You can set price alert (for Banggood).
That coupon does not work in UK
That’s true. Sorry about that!