The Temptag® Pro is best hand washed only. Avoid using strong chemicals, scourers and steel wool directly onto the Temptag® to prevent surface damage. If the surface is broken, replace with a new Temptag®. It is expected that the Temptag® will display accurately for 4-6 weeks depending on care and usage. If the black window appears grey of cloudy or the Temptag® bubbles or begins to peel, we recommend you replace it to maintain consistency.