TomTop offers the Meterk GFCI Electric Socket Tester for $3.99 with free shipping. That's slightly below our mention of a similar model from earlier today and the lowest price we could find now by $2. It features LED light and test indicators. Deal ends May 31.

Note: This item ships from China and may take up to four weeks to arrive. The countdown timer on the product page does not reflect an actual expiration time and resets daily.