I tried 6 of these mice. The shape is literally the only good thing about it. The sensor failed, I had double click issues with the M1, I had issues with the M1 not registering at all, and finally they all had issues with an accurate battery gauge. Charge to 100 and be 50%, charge to 100 and be 50%. It constantly charges the battery, which is guaranteed to fry it VERY quickly. For $150 it's a scam.