Measurement Category: CAT IV 1000V, Frequency range: 50Hz~60Hz, Indicators: LED and beep, Voltage range: AC 90V~1000V, Brand name: UNI-T, Model number: UT12B.
Basically copy coupon, view price history or create e-mail price alert. What is the best price?
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.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($12.75): BGherra
2. ($12.75): BGHERRA
just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): TTxBG10, AFfbG10, BG15METER, BGAFF10OFF, bGhOnEy10
(probably won’t work, but you can try them out)
Price history and price alert
Do you need price history chart (for all/most countries) for UNI-T UT12B Voltage Detector Pen? There we go. The lowest price was: $7.66.
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)).