Achieving the perfect roast is just a few degrees away. Accurately measure your meat preparations by following the temperature guide. The simple design allows you to pierce the roast and leave the thermometer inside the meats while in the oven. The leave in thermometer measures from 140 to 190 degrees Fahrenheit (60 to 88 degrees Celsius). The 3-1/2 inch probe cover enough distance to reach near the bones of your roasts for a proper reading.