IceCap ATO EZ Automatic Top-off SystemThe IceCap ATO EZ System is an easy to use pump and sensor combo that offers peace of mind when replenishing evaporated water to an aquarium. Its twin optical sensors extend the devices life and reliability by limiting the frequent powering on and off of the refill pump. This system also includes a third (safety) sensor that provides another level of security to prevent overflows. The IceCap ATO EZ is a well thought out automated system with a fail