1. WIDE USE. Match all types of energizers. Can be used on any type of electric fence including steel, wire tape etc. 2. . Do not need to touch fence wire. Just BUTTON and hold it close to fence, it give a loud beep if the fence is active. Working distance about 20cm near fence. 3. UPDATE BEEPER. Add on-off button and light. Flash be useful when in dark places or in the evening. Pocketable design Requires 3 Volt CR2032 button Battery Operation (Not Included) 4. LONG LASTING. Simple compact design could avoid falling damage. Made from solid materials with a replaceable battery and keyring attachment., Weight: 0.04299014109 pounds, Manufacturer: Qusedwey