The document describes the T600xxx-3 Series thermostats, which provide temperature control for heating and cooling equipment. The thermostats come in both non-programmable and programmable models for single-stage, heat pump, multi-stage, and economizer applications. Key features include an LCD display, simplified setpoint adjustment, configurable parameters, and compatibility with remote sensors. The thermostats use a proportional control algorithm to regulate temperature and include specifications for power, inputs, outputs, temperature range, accuracy, and dimensions.