Bubble Magus NAC6 internal skimmer features an air nozzle to adjust air mixing ratio for dense foam, needle-wheel impeller, bubble plate, easy to remove collection cup and easy access Atman ph2500 pump. Perfect for aquariums 100 - 160 gallons. Measures 10.4 in. x 6.7 in. x 19.6 in. with a 6 in. cylinder.