Comment by seemaze

A microfiber cloth apparently so notable that it even has its own Wikipedia page:

https://en.wikipedia.org/wiki/Apple_Polishing_Cloth

Pay attention to the compatibility list though. If you use the Cloth™ on an iPhone 4 or earlier then you're in uncharted territory, who knows what could happen.

You bought a car that requires premium grade fuel, you gotta pay for the premium grade.