A pump safety switch is a great device that turns off the pump if there is not enough water. A safety switch is plugs into an outlet and the pump is plugged into a connection on the safety switch. If the safety shut off senses there is very low water, it turns off the electricity going to it and therefore, also the pump. When aquatic pumps run dry, they can quickly burn out.
The pond should not sit low on water with the pump off for any extended period of time. Stagnant water is not good for the health of the whole system. Having this device can save the pump if the water gets too low.
If you want protect your pump while you travel this may be the answer for you!