Most deep-fat bi-metal temperature probes of this type are junk, made overseas. This is my third one. Most are made in China; this one is made in Vietnam. Probes of this type are generally off by 10-40 degrees F, right out of the box, and if you drop it, or it's dropped during shipping, forget about it. These units have all the problems that wind-up watches had until quartz movement came about. This one, like many others, has a nut at the top of the probe, just underneath the dial, that you can crank with pliers to make the temp reading accurately correspond to the temp of the measured object (I used boiling water). I test all of this type probe in heated water on the stove. With the probe inserted into the water, when the water reaches a rolling boil, if the needle indicator is not at 212 F or 100 C, use the pliers as you hold the dial still to adjust the dial indicator needle to the boiling point of water. This will at least make this unit accurate at 212 F, but don't forget the unit might not reflect the ambient room temp accurately when allowed to cool (my house is maintained at 76; unit shows 100 room temp although calibrated to show boiling water at 212) and may not accurately indicate frying temps of 300-375. The US does not offer a quality unit of this type. You take your chances with all of these, whether you spend more or less than the cost of this unit. The best solution is to stop relying on these cheaply-made unreliable bi-metal probes, and to spend the money on the Thermo-pen Mk IV probe. I won't review that unit here, but a quick search will lead you to the correct official site. As for this unit, I've got it dialed in to accurately reflect stovetop boiling water, but, as I stated above, this is no guarantee this unit or others like it will be accurate at deep-fry temps. I will use my Thermo-pen to test the accuracy of this unit in boiling oil. I will post the results here. Update: I have calibrated this unit with my super-accurate, expensive themo-couple device. As expected, inaccurate under 200 degrees. However, accurate over 300 degrees, which is where one starts to actually deep-fry. As long as I can have an accurate deep-fry probe for the range of 300-360, I am happy. I am happy with this unit, as verified by my thermo-couple tester.