All Geosub Pump systems require a controller and connecting cable (stock # 86238). SS Geosub controller provides safe, conditioned variable DC power from an AC power source (optional DC/AC inverter, stock # 86239, lets you run power from a vehicle battery). Use the controller to precisely control water sampling flow rates from high purge to low flow, down to 10 mL/min. Controller features an easy-to-use interface and bright display. It stores and recalls 80 site-specific settings for efficient, repeatable sampling. User settable dry-run protection automatically turns the pump off if it becomes unsubmerged. Note: Flow rate must be above 0.1 gpm to use dry-run protection.