The Johnson Controls T-4002-201 Thermostat is a pneumatic thermostat designed for use with central furnaces and central air conditioners. It features a rectangular shape with a gray color, dial control style, and adjustable thermostat capabilities. This thermostat is compatible with Johnson Controls brand products and has a wall-mounted design for easy installation. With a heat-off system switching feature and non-programmable programmability, this thermostat is a reliable choice for controlling the heating and cooling systems in various industrial and commercial settings.