Marine Metal 2-Way Bubble Quiet Aeration System, B17: * Extremely quiet aeration system * Operates 52 hours on 2 D cell batteries * 12 VDC adapter port (included) * 110 V adapter port (adapter available at Radio Shack) * Powerful 3 VDC motor pumps up to 1.39 liters of air per minute * Aerates 5-10 gal * Water-resistant case with neoprene seals and a booted waterproof switch * 30" of soft silicone airline tubing with weighted glass beaded airstone * Adjustable stainless steel mounting clip and fasteners