Are you noticing higher temperatures in your 2001-2016 Silverado Sierra 2500HD 3500HD 6.6L Duramax truck lately? Has your truck accumulated high mileage? Consider replacing your thermostats with DmaxStore High Flow Thermostats - they are a direct fit for GM originals. Designed to open at the same temperature as stock, these thermostats open faster and allow for increased coolant flow. This helps lower the temperature of the coolant more quickly when it gets hot, maintains a steady temperature, and reduces strain on the water pump impeller. We highly recommend these thermostats, especially when upgrading your water pump and other components in your cooling system. Includes: - 185ºF Thermostat - 180ºF Thermostat