This smooth streamlined design will keep your Twin Cam running cooler on those hot summer days in stop and go traffic as it drops your cylinder head temperature by as much as 100 degrees Fahrenheit (55°C). Although this mounts in the horn area Jims has designed a horn relocator hidden inside the fan housing. The fan can be installed to be turned on and off manually or it can be regulated by a thermostat controlled sensor that monitors head temperature and activates the fan when needed. This kit is highly recommended for performance motors to help extend engine life. Complete kit includes high powered fan, housing, horn, hardware and all wiring, along with detailed instructions. Fits all 1999 to present Touring Models, adapts to most other models with some fabrication.