ARO Drum Pump Package. EXPert Series DAB05. 1/2" Diaphragm Pump, 11 GPM Flow Capacity, 1:1 Ratio, Drum Mount. Polypropylene Pump Housing and Seats, Santoprene Pump Diaphragm and Balls. Package includes: Pump, Bung Adaptor, Air Safety Shut-Off, Siphon Tube, Weather Seal and Base.ARO Drum Pump package components contain pre-specified, matching materials of construction for complete fluid compatibility. This package is compatible for use with mild acidic fluids. Please refer to the chemical compatibility guide for the specific material you are pumping.