Accurate, continuous monitoring of waste holding tank contents is vital to boat owners. The Dometic DTM04 tank monitor offers unparalleled reliability and ease of use. A single glance is enough to check the available holding tank capacity with no more false readings. The system features an easy-to-install three-probe float switch with cap and wall-mountable display panel with four-color LED indicator. The display indicates empty, low, mid, and full tank status. An optional relay to shut down electric toilets in the event of a full tank is available. DTM04 panels can connect with DTD tank discharge control to offer convenient holding tank discharge options. Includes one set of tank probes. Available with or without ventilation.