Measure take from this cover from IKEA: https://www.ikea.com/at/de/p/prickig-mikrowellendeckel-grau-70186090/
I have added some grooves to fit a 19.2mm double sided tape for mounting. Of course you need two of them for this to work. Printed in 0.2 and 10% infill.
The author marked this model as their own original creation.