Gemtech GT110d is a non-programmable thermostat designed for 1-Heat / 1-Cool systems. It features a simple user interface with a large display, temperature adjustment buttons, a system switch, and a fan switch. The system switch allows you to select between cooling, heating, and off modes, while the fan switch lets you choose between automatic and continuous fan operation. The thermostat also has a low-battery indicator to remind you when it's time to replace the batteries.