Feature: 1. Plug and play, real‑time safety detection of the current line, and one‑key testing of the working status of the leakage switch protector. 2. Voltage value display, preferably high‑definition LCD material, with backlight function, clear writing. 3. Carry out safety hazard investigation and acceptance of electrical sockets in homes, offices, and factories. 4. Exquisite appearance, mini size, easy to place and carry without taking up space. 5. Using high-quality materials, strong and durable, has a long service life. Specification: Item Type: Socket TesterMaterial: ABS+LCD Size: Approx. 6.5 x 6.1 x 6.1cm / 2.6 x 2.4 x 2.4in Instructions: 1. Detect whether the socket is leaking 2. Detect whether the leakage protection switch fails and press the wrong button 3. Detect whether the wall socket wires are aging, broken, crossed, etc. 4. Check whether the power strip can be used normally 5. Check whether the circuit is lack of wires The Corresponding Test Result Description of Indicator: The left and middle red lights are on, and the line is connected normally; The red light on the left is on, the line lacks a ground wire, and there is a safety hazard; The red light in the middle is on, the line lacks a neutral line and cannot be used normally; All unlit means that the live wire and the neutral wire are reversed; The middle and right red lights are on, indicating that the live wire and the ground wire are connected reversely; The red light on the left and right is on. The line is missing or the line is not connected to the grid; All lights up indicates that the ground wire and live wire are not connected; Test Whether the Leakage Protection Switch Works Normally: 1. No tripping and no leakage protection 2. Tripping leakage protection is normal . Package List: 1 x Socket Tester 1 x User Manual Note: Manual measurement, for reference only.