The Z-Bulb Electric Fence Light works exactly like the LED Fence Light but is designed for fence chargers that are 3-Joule or larger. The larger the charger the brighter the light becomes. The bulb is guaranteed for 3 years but should last a lifetime. This does not cover lightning damage. It only draws current off the fence until something such as a animal or person touches the fence. When this happens the light will disengage and the full shock will go directly to the animal or what ever is touching the fence. Made in USA, Cookeville TN.