Check the listing for details. Honeywell The Round Manual Thermostat CT87B 24V Gas Oil Hot Water Heat/Cool. Color: White, Condition: New. Listed at 40.00 USD. The Honeywell CT87B 24V Round Manual Thermostat is a wall-mounted thermostat designed for use with gas appliances. It features a classic white color and operates on a 24V power source. The round shape adds a modern touch to the traditional thermostat design. With its reliable brand reputation and specific model number, the Honeywell thermostat is a dependable and efficient choice for controlling heating and cooling systems in the home.The Honeywell CT87B 24V Round Manual Thermostat is a wall-mounted thermostat designed for use with gas appliances. It features a classic white color and operates on a 24V power source. The round shape adds a modern touch to the traditional thermostat design. With its reliable brand reputation and specific model number, the Honeywell thermostat is a dependable and efficient choice for controlling heating and cooling systems in the home.