1. Self testing before use: Close the tester probe to any hot line, detector will light up together with buzzer sound. If the light and sound are weak, please replace the batteries inside 2. Test voltage present: Close the test pin to live parts, the tester will light up together with sound 3. Replace batteries: Please refer to the following picture to replace batteries 4. Do not place the tester near high voltage warning: A. Check before use B. Never test the voltage which than 1000V AC C. Test voltage range: 90V-1000V AC D. IP54, IEC 1010 E. AAA 1.5V/2PCS(not included) F. Battery life: 6 hours for continuous using standby for 1.5 yearsSpecification: Package Weight One Package Weight 0.05kgs / 0.11lb One Package Size 20.8cm * 9.3cm * 1.4cm / 8.19inch * 3.66inch * 0.55inch Qty per Carton 80 Carton Weight 5.00kgs / 11.02lb Carton Size 40cm * 23cm * 30cm / 15.75inch * 9.06inch * 11.81inch Loading Container 20GP: 966 cartons * 80 pcs = 77280 pcs 40HQ: 2242 cartons * 80 pcs = 179360 pcs