All electrical parts and thermocouples are non-returnable. Please make sure you are buying the right one. While Type-K thermocouples are all the same electrically, the kiln manufacturers use different styles, lengths, diameters, and also add mounting hardware for particular applications.
Therefore, thermocouples are not plug-in compatible/ interchangeable with one-another. It's important you purchase the correct one for your brand/model of kiln.
We stock some thermocouples but not all. Some are direct shipped from the manufacturer.