Marine Metal Products Bubbles: * Water resistant air pumps that aerates up to 7-1/2 gal * Pumps 7/8L of air a minute * Runs quietly on 1 or 2 D cell batteries * Adjustable stainless steel clip and fasteners * Individually tank tested * Weighted airstone * Beryllium copper batter contacts * Diaphragm pump * Fresh or salt water * Precision motor runs 85 hours on 2 alkaline D cell batteries * Booted waterproof switch * Weighted glass bead airstone with 30" of air line tubing * Made in America * Space saver package dimensions: 5-5/8"L x 9-1/2"W x 2-1/8"H