Compressed air drum pumps are manufactured in 316L Stainless Steel. The Reversible Drum Angel/ Drum Pump is a maintenance free system to recover spilt liquids, coolant, sludge, tramp oil, wastewater and other liquids using only compressed air. The compressed air system attaches easily to any closed head of a drum (30 or 55 US gallon, or 45 Imperial gallons or 205-litre drum) The reversible feature allows you to fill or empty the drum in under two minutes with the simple turn of a knob. Using no electricity, the Drum Angle unit, which is connected to the small hole on the top of a closed metal drum, instead of vacuum, the unit creates a pressure inside the drum to push out the liquid.