ATV owners, listen up. If your radiator fan isn't turning on when it should, this little sensor might be the culprit. This is a replacement temperature switch (or thermo switch) that's compatible with a ton of Yamaha ATV models, mainly the Grizzly 400/450, Kodiak 400/450, and Wolverine 450 from the mid-2000s to early 2010s. The part number it replaces is Yamaha 5ND-82560-10-00. It screws into your engine or radiator and basically tells the electric cooling fan when to kick on based on the coolant temperature. If yours is faulty, your engine could overheat. Caltric is a big supplier of aftermarket powersports parts, so this should be a decent quality, affordable alternative to the OEM part. Installation is usually pretty straightforward if you're handy. PLEASE double-check the massive list of compatible models in the description to make sure it fits your specific year and model ATV. A small part that can save your engine from big trouble!