LCD operating voltage: 220v ± 20V, RCD current: > 30mA, Working temperature / 0-40 ° C, Storage temperature: -10 ~ 50 ° C, Storage humidity: 20-80% RH, Working voltage / measuring voltage range: 90-250v / 45-65Hz, Measuring voltage accuracy: ± (2% + 5), Altitude: <2000 meters, Working hum heart ty: 20% -75% RH, Whole machine working current: <3mA (not in RCD status). Price history, coupons and price alert are available on this page. What is 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 price update (UTC time):
Banggood
Banggood warehouse is located in Europe 
. Uhm… There’s no price history (in my database) for this product right now. There is one coupon available! Pretty cool, huh?
Link: Banggood product page
1. ($12.59): BGTOOS729
this code has to be applied in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BG55a773, BGGines, BG55da75, BGM1TOOLS88, BG20236Tool
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. China – Mustool MT10S MT10E Socket Outlet Tester ($-3)
Price history and price alert
It’s a new item in our database, so I can’t create price history chart. We have saved this price in database: $7.99.
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)).