Product Description: Water Resistant Air Pump. Runs up to 33 hours on 2 alkaline 'D' cell batteries. Space saver clam shell package. Aerates up to 7-1/2 gallons. Pumps 7/8 liter of air/minute. Adjustable stainless steel clip and fasteners. Individually tank tested. Weighted airstone. Beryllium copper batter contacts. Diaphragm pump. Fresh or saltwater.