1. WIDE USE. Match all types of energizers. Can be used on any type of electric fence including steel, poly 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 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: Blisfulhoks