The Napa 183 thermostat is a bolt-on copper thermostat with an opening temperature of 195°F. It is designed for vintage Alfa Romeo Giulia Berlina Duetto 1600 Standard models and has an item width of 54mm. The thermostat is durability tested and does not require drilling or modifications for installation. It is an OEM replacement part with interchange part numbers THM 183, 530090, and 183. The Napa 183 thermostat is made in the United States and is not a universal fitment or a performance part.