The Silent Air Battery air pump from Penn-Plax is a real lifesaver This pump runs on batteries to provide a dedicated source of aeration for aquariums and more. Aquarium air pump runs on 2D batteries with continuous operation up to 96 hours. No electricity is needed so the pump can also be used for fishing. Pump will only operate when manually turned on and provides a constant supply of necessary oxygen to fish in an emergency. Aquarium air pump is safe to use in tanks up to 29 gallons. An air pump is also a great option for transporting fish. Unit is compact and impact resistant. Air tubing and stone are included for easy setup. A check value is recommended but not included in the kit. The pump is safe for both freshwater and saltwater environments.