Thermostat for Toyota Hilux 2TZ/3RZ - 2.4L and 2.7L - Tama WV56TC-76.5

As you can see in the photo, this type has a bypass-valve on the bottom. It is mainly used in Inlet of the engine cooling circuit. As water temperature rises in the engine, the bypass-valve slowly shuts bypass hole. This allow more water to flow into the radiator. These days, most engines use this type.