1. Pull battery type cover makes it easy to replace the battery 2. Automatically distinguish the Zero Line and the Fire line 3. Sound and alarm LEDs 4. Automatic selection of 3 types of sensitivity. (High, Medium, Low) 5. Professional AC Voltage Detector with Non-contact test 6. Voltage sensitivity is from 12 V to 1000 V AC 7. The AC voltage sensitivity is adjustable 8. Sound and light instructions 9. Auto power off 10. Safe, professional and easy to use 11. small and compact pen that has been designed for easy transport Specifications: Technical specifications: 1. Voltage Sensitivity: 12 V AC to 1000 V 2. Frequency: 50-60Hz 3. Alarm Mode: Sound and light 4. Flash of Light: White Power 5. Auto Off: Yes 6. Operating Temperature: 32 to 122 & # 8457; (0-50 & # 8451;) 7. Storage Temperature: from -4 to 140 & # 8457; (-20 to 60 & # 8451;) 8. Humidity: 9. Battery: 2x1.5V AAA batteries (Not included) dimensions: 15x2.6x2.4 cm quantity: 1 Pcs Package Included: 1 Pz x Voltage Tensioner Voltage Pen