I use the Beurer thermometer which is an excellent product all round. I purchased replacement covers for the measuring top recently, as these do visibly wear with use. As the maker states. Mine arrived promptly, well packed and are identical to those supplied with the thermometer. I bought two ten packs which should last a good time. If you are using the thermometer for personal use it would possibly not require very regular changes of cover, but the unit senses the cover and will not work without one in place. Presumably it is calibrated to work with a cover? Happy with the cost of these items and the service.