HANNA BlackStone's Positive displacement Solenoid Driven Chemical Dosing pumps have been designed to meet the ever-changing needs of the industry. With their broad, flat base and mounting holes for the tank, shelf or floor mounting (horizontal), the pumps can be easily mounted anywhere in your plant. The rear of the pump housing also provides mounting holes to facilitate vertical mounting: wall, tank or machine. Since the pump valve assembly and controls for the unit are located on the front of the pump, there is never a problem with the installation or flow adjustments.