Some call it Thumb Sleeves, others say it’s Mobile Gaming Finger Sleeves- whichever one you call it, doesn’t matter because they both refer to the same thing that performs same function.
Thumb Sleeves are usually worn by some streamers and if you think it’s because it looks cool and fashionable you’re not entirely wrong, but there are many other reason why gamers use it.
If you’re used to playing mobile games over an extended period of time (like hours) your palms and fingers tend to get sweaty. And as sweat touches your phone screen it gets sticky and dirty, and sometimes prevents you from freely swiping your thumbs (or fingers, for claw players) across your screen while gaming. When this happens, you will have to pause every now and then to wipe your screen, which leads to a no-fun gaming experience.
Some of the gaming finger sleeves can be worn on all your fingers (perfect for claw players), and this helps you maintain firm grip of your smartphone while gaming. It also ensures that your phone doesn’t slip off your hands even when sweaty, because the sleeves absorbs all the sweat.
Thumb sleeves also helps prevent scratches on your screen if you have untrimmed fingernails or, dirty or rough thumbs that can easily scratch your phone screen. Although, not all phones screen scratches that easily, and not everyone use phones with Corning Gorilla glass, and the likes.