<b><br />Motorcraft RT1121 Thermostat Asy:</b> <br /> <ul> <li>Heavy-duty quality for long life</li> <li>Stainless-steel or brass bridge and spring frame, channel-constructed for strength and rigidity</li> <li>Stainless-steel, tapered-end pistons with flexible elastomeric boots</li> <li>Car spare part has a streamlined venturi nozzle for maximum coolant flow</li> <li>Brass cover and guide for heat motor piston</li> <li>Mounting-flange designed to properly fit and seat the thermostat in the housing</li> <li>Stainless-steel spring offers precise operating compression</li> <li>Heat motor in high-strength brass housing</li> <li>Rulon seal for heat motor piston</li> <li>Specially formulated expansive-wax compound</li> </ul>