The PuK Thumbstick interfaces with your device screen on a specially selected self-lubricating Nylon disk and a traditional touch display stylus. Our extensive testing shows that the long term effect of this on your display is very minimal. In fact, our testing shows that long term, a mobile gaming thumb sleeve is more abrasive than our Thumbstick.
For peace of mind, you might choose to use a screen protector on your device. This should work great as long as your screen protector made from Tempered Glass. Although, if you’re using a PuK Thumbstick with PuK Compatible Triggers you may find multi-touch issues on some devices. So far, only Apple devices have shown this issue in our testing.