After the purchase, I recommend immediately upgrading, inserting a piece of foil and an AAA battery. This will significantly facilitate the rodent, because it will constantly slip out of the hand. The hand strains, trying to hold it. I also glued pieces of double tape on the sides so that my fingers had something to grab on to. Unfortunately the plastic is very slippery and the shape of the mouse at the ring finger suggests that it will slip out. After these manipulations, the hand ceased to strain from long work. Otherwise, I can praise the quality, after a month everything works like clockwork. Accuracy and glide are pleasing.