Sierra 18-3569 Mercury Thermostat Kit Sierra replacement thermostat kits are designed to meet OEM specifications. This kit fits various Mercury/Mariner 70-125 HP 2 cycle outboards (1987 and newer). Temperature rating: 120F; Kit Contains: (1) 18-0182 Thermostat Gasket; (1) 18-0339 Thermostat Gasket; (1) 18-3549 Thermostat; For Use On Mercury Engine Models: 70 3 cyl. A996142 & UP; 75 3 cyl. C222000 & UP; 80 3 cyl. A996142 & UP; 90 3 cyl. A996142 & UP; 100 4 cyl. B209468 & UP; 115 4 cyl. C100000 & UP; 125 4 cyl. D283222 & UP; Interchangeable with: GLM; 13124; Mallory; 9-43155; Mercury Marine; 803061T1;