Marine Metal Products Hush Bubbles Portable Aerator aerates up to 7.5 gal. and pumps 7/8 liters of air/minute. It runs quietly for 33 hours on 2 D batteries and has a waterproof switch. The pump is protected by a weatherproof case, comes with weighted glass bead air stones and has large adjustable stainless steel mounting clips. Aerates up to 7.5 gal. and pumps 7/8 liters of air/minute Runs quietly for 33 hours on 2 D batteries Protected by a weatherproof case