I think its because of the spinning magnets. Im using these for makeup touch-up especially around the eyes. UPDATE: 4/4/2020Do not buy this mouse until they fix their unusable Logitech GHUB software. Como le ha ocurrido a otras personas, se me ha despegado la banda lateral. I wore them, didn’t break them in first, and they were the business. (Sidenote: a lot of these stickers seem to be based on fan art which is concerning to me because theres no artist credit anywhere?) We walked each day & up to 7 hours one day at the zoo. Hope this helps for whoever is looking. I have had these for a day and so far are alright, not the greatest, especially for $50. I liked the idea though.