A microchip is a permanent pet ID. The microchip itself has no internal energy source, so it will last the life of your pet. By taking the lost pet to your local veterinarian ,It is read by passing a microchip scanner over the pet's shoulder blades. The scanner emits a low radio frequency that provides the power necessary where the chip is located to transmit the microchip's unique cat or dog ID code and positively identify the pet, so it can find its way back home