Description: The oxygen pump with built-in a rechargeable lithium battery for storing energy, thus the oxygen pump works outdoor as well, it can be powered by a power bank, computer, car charger, etc. Suitable for a small-sized pond, outdoor fish tank, etc. Features: [Two Power Supply Modes]In the case of full power, continuous mode up to 15 hours of working time, indirect mode working time of 30 hours. [Large Air Volume]Stable silent oxygen pump with 3L/min or 6L/min air volume, provides a sufficient amount of water circulation in your aquarium. [Quiet]The aquarium air pump is made of ABS thickening plastics, a super silent air pump. [Portable Buckle]Come with a buckle, can be hooked on your bag, fishing box, aquarium when moving. [Widely Applicable]Suitable for a home aquarium, outdoor fishing, air pump back up, aquarium transportation, pond. Specifications: Types: Type 1; Type 2 (Optional) Material: ABS?? ?, Electronic Component ? Color: White Battery:3.7V, 1100mAh(Type 1), 3.74V,