This is a new, unused e-AIR 1000SB. Suitable aquarium: Water depth of 35cm or less, S/M/L compact aquariums It has a special sealed structure that prevents internal noise from escaping, and a silent design with anti-vibration rubber feet that minimizes vibrations transmitted to the ground. Usable air tube: 5mm outer diameter, 4mm inner diameter air tube We will ship within 1-2 days after your order.