B&G Pressurizing Tank Top is designed to maintain a reliable and steady pressure in your spray tanks from filling to empty with the battery operated pump. With the use of this device, pumping is no longer required. There is an on-demand pump that cycles on-off to pressurize and provided better control and residue. This product delivers up to 40 gallons before needing a battery recharge. Recharge battery once every 4 hours with battery charger included. Fits and attaches to all B&G stainless steel tanks.