Display: 0.28 inch LED, Measurement rate: ≥200mS / times, Red line is the input positive, Working current: <30mA, Installation hole: 23 × 10 mm, Black line is the input negative, Detection voltage: DC2.5V ~ 30V, Accuracy: 1% (+/- 1 word), Dimensions: 31 × 12.0 × 9mm (lengthx widthx height). Go down and check coupons out. Remember to check price history if it is available. What is best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
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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. There is one coupon available! Pretty cool, huh?
Link: Banggood product page
1. ($7.56): BG00c906
apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Price history and price alert
Here is price history (for all/most countries) for 0.28 Inch 2.5V-30V Mini Digital Volt Meter. The lowest price was: $2.99.
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)).