Yellowed and leads to faulty operation

The sleeve fits and protects. But after a few weeks using it looks unsightly yellowing, although we are a Non smoking household. In a snow-white cell phone that acts as attractive as dental plaque.

Particularly annoying: The lock button on your phone is not left out, so they operated accidentally repeatedly in light lateral pressure on the shell.

Now the shell is unused in the drawer, waiting for possible use in a backpack or bicycle bag, eventually. As a consolation, the low purchase price.