$27.99 – 3 IN 1 Vibration Button Controller Heating Vibration Knee Pad Shoulder Pad Elbow Pad Intelligent Temperature Control Vibration Massage Moxibustion Hot Compress Instrument – Gray.
ATM you can buy 3 in 1 Vibration Button Controller Heating Knee Pad for $27.99 (in Banggood). Go down and check coupons out. Remember to check price history if it is available. Best price?
Latest coupon code price check (UTC time):
Banggood ($27.99)
Banggood warehouse is located in China. There are no coupons available at this moment in Banggood. Isn’t it too expensive? Well, this price is higher than average price ($24.79)
Link: Banggood product page
Price: $27.99
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BG1ec683, BGbf734c
(these codes were not working in latest coupon update, but you can check them out anyway)
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
Check out price history chart (for all/most countries) for 3 in 1 Vibration Button Controller Heating Knee Pad. The lowest price was: $23.99.
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)).