Unlike the Eternico MVS390 mouse, which this mouse replaced after a month of waiting for stock, where the scroll wheel starts to skip after a while of use (tested on 5 units over the last years), this mouse gives a much better impression, especially with the mouse wheel. The wait was worth it and with the mouse I am (so far? ) very satisfied. So far I have come to a few observations that may be useful to some. The backlighting can be turned off by holding the button on the bottom of the mouse for about 5 seconds, and by clicking you can switch colors between "smoothly changing color", "faster smoothly changing color", "fast changing bar of different colors". Nothing else, a uniform permanent color unfortunately cannot be set. Colours are changed only by button, not via any software. There is no software for the mouse and there is no need for it. Fortunately, I'm not interested in color at all, and given that vertical mice are not at all suitable for gaming, I don't see what group RGB backlighting is even targeted at. Without the backlight, or with a permanently switchable backlight, the mouse would look even better. For the sake of battery life, which is integrated in the mouse, it is therefore not necessary to replace the AA pencil batteries and just charge the mouse once in a while just like the phone, just turn off the backlight. I've been using the mouse for about a week +-12 hours a day and haven't had the privilege of charging it a second time yet, so +1. The charging connector is slightly hidden in the mouse chassis, some USB-C cables may not fit, but most are fine. The supplied USB-C cable is shit though, and I don't feel like it would hold the mouse plugged in well, so I use a different one. I didn't buy the mouse for the USB-C cable anyway, and I have plenty of USB-C cables anyway. Note that the USB receiver is not under the cover, but only inserted into the bottom of the mouse. But since the mouse can also handle Bluetooth connections, it's not always necessary to carry a USB receiver with you. There is also an off/on switch at the bottom, a side round button to change the device from USB receiver to Bluetooth, and a button by the mouse wheel to change the DPI.