This adorable product uses an adapter that is fixed directly to the power supply, rather than using batteries which may run out frequently or unexpectedly. The current is safe because it is low voltage, and its not at all harmful for the cat by any means, so there is no chance of short circuits, even if the cat chews or pounces on the lead, as the voltage is very low. Even if the cat flap is disconnected from the power it will always remember your cat's microchip numbers.
Jun88v1 
