The Davies Craig in line adaptor allows fitment of 1/4" NPT temperature sensor or an air bleed fitting to be fitted. The adaptor is easy to install and fits directly into the top radiator hose at the highest point. Fits radiator hoses with a  35mm or 38mm internal diameter.2x 1/4" NPT portsProvides easy fitting of coolant temperature sensorsUniversal fitting and suitable for radiator hoses of 35mm or 38mmAllows air to be bled from the cooling system improving performance and reducing the risk of overheatingThe in line adaptor is suitable for bleeding the air from a vehicles cooling system which is essential for the system to operate at its full capacity. Most modern vehicles have air bleeds installed as standard. This adaptor is ideal for older vehicles which do not have air bleeds.