$15.99 – HT662 Brake Fluid Liquid Oil Tester Analyzer Meter for DOT3/DOT4/DOT5.1 Brake Fluid Content Detector.
$15.99 – that is current price with coupon for HT662 Brake Fluid Tester (in Banggood). Go down and check coupons out. Remember to check price history if it is available. What is the best price?
Latest coupon code price check (UTC time):
Banggood ($15.99)
Banggood warehouse is located in China. As you can see I didn’t find any active coupon for this product right now… Low/high price? Maybe there’re no more promotions for this item, because current price is higher than average (which is equal $9.12)
Link: Banggood product page
Price: $15.99
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BGAMMT03
(you can check these old coupons out, but these probably won’t work)
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 HT662 Brake Fluid Tester. The lowest price was: $5.65.
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)).