Just a quick note here. I’ve had a USB mouse with an “air flow fan” to get air conditioning to your hand when it is on it, but I was having trouble that the fan was being noisy. As part of a repair for fixing its frayed USB cable due to my fault of bending it too sharply at the mouse-side, I opened up the mouse and found out that the sticker on the fan came loose. Well, no wonder why the fan was noisy! That sticker dangling around could make quite a bit of noise I’d bet. Also, there was quite a bit of dust around the fan, that’s another opportunity for cleaning.