For instant reassurance that your fence is working. Place permanently on your fence line and simply look for the flash (flashes with each pulse of the Energizer) when you pass by. No batteries required. Brand Name: Gallagher Product Type: Live Fence Indicator Color: Black Material: Plastic Water and UV resistant for long life Quick and easy installation- simply place ground stake in the ground and clip onto fence wire or tape Easily visible during day and night (up to 3 000 : Easily visible during day and night (up to 3 000 at night) Install at strategic locations for convenient visibility including driveways and near the home No batteries required- uses power from the fence ?Weight: 2.4 lbs. Highly visible LED flashes to indicate fence is working effectively Low voltage cut off so it will not flash if the fence voltage is too low