Use the Bluelab® External Lockout & Alarm Box to connect the Bluelab® Pro Controller™ to external switches, for example - a float switch or a greenhouse alarm system. When these switches are activated, the Bluelab® Pro Controller™ is placed in lock out mode, so no further dosing will occur until reset. Comes with built in alarm which can be disabled if required. It can be connected to an external alarm (horn or flashing light).
— Ships from H: WA, CA, CO, MI, TN, PA, FL USA (No USPS).
For more information, please visit the manufacturer Bluelab's website.