Thermostat Kit 825212A1 is a 120 F degree thermostat kit is for Mercury and Mariner 30hp 4-stroke outboards (1999 - 2005 USA made 0G760300 - 1B226999; 1999 - 2005 Belgium made 0P017000 - 0P400999), 40hp 4-stroke outboards (1998 - 2018 USA made 0G231123 and up; 1999 - 2018 Belgium made 0P017000 and up); 50hp 4-stroke outboards (1995 - 2000 USA made 0G231123 - 0T178499).Mercury Marine's passion for performance is matched by your drive for the new, the unknown. Our legendary reliability and durability let you boldly embrace your next adventure—large or small—knowing you're backed by the best quality design, engineering, and materials.