The roof liner is a protective surface plate applied to the roof area of the inside of the unit. It is reflective to divert microwave beams around the unit and can be easily bought in a cut to size format. The liner also protects the wave guide from residue food and beverage spatters, dust, and the general grime that builds up over time. Most food produce some grease and/or steam during the cooking process which builds up on the inside of the unit. Keeping your microwave clean is very important and the roof liner makes this easier by covering tricky components. It is possible for the magnetron to short out should other elements become choked with food residue and grease.

Company resources：PTFE sheet, oven liner
Read more：http://www.ptfeglassfiber.com/news/