The Stelpro ASSO Sonoma wall fan heater offers three controls types including a built-in thermostat, built-in timer, or without control option. Stelpro strongly recommends an electronic wall thermostat for those heaters without controls. If installing in bathrooms, use models with a built-in timer and thermostat. Stelpro ASSO wall fan heaters offer these additional features: Impact-resistant front Retrofits most popular models Recess mount or wall mount with surface adapter Thermal protection with manual reset and thermal fuse Rapid temperature increase Controls placed at the top of the unit Quiet heat One-screw cover installation