I have already bought 4 of these mice for the whole family - everyone was happy. And I had to urgently buy for myself in the offline Amazon store, as the old one refused to work. I came across a very strange specimen: where the connection between the upper and lower parts of the case goes, you can feel the sharp edges of the plastic, which is very unpleasant and very frustrating. This was not found on other mice of the same type. Unfortunately, I bought in a business trip city and there is no way to make a return. Check immediately after purchase.