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Product Net Weight 72g, Brand PGG, Rated Voltage 5V, Battery 450mAh Lithium Battery, Item Model Number D18A, Product Size 105*157*55mm, Product Color White/Blue/Gray/Red, Rated Power 5W
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. I can’t find any active coupons for this product in Banggood.
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!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG2d3876, BG75597c, BG589b2e, JanBGCoupon8, BGSaleFeb8, BGAUGUST8, BGCAPITALOS8, BGCOUPERT8
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for PGG D18A Pocket Foldable Cervical Massager.
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)).