These devices are meant to keep an oxygen supply to live bait on the way to your fishing point or whilst fishing. Both models are battery powered, but the larger model can be powered by a 12V source - either a cigarette lighter plug or battery clips. (Batteries not included; see page ?? for D cells) This unit is powered by a single 'D' type cell. If the cell is an alkaline one and is new (fresh) you will get approximately 48 hours of running. It is supplied with 700mm of tubing with an "air stone" (aerator) at one end and a two speed air pump. The aerator case is waterproof, sealed with a rubber 'O' ring gasket. Measures 105(H) x 80(W) x 40(D)mm Accessories: Belt clip