Amazing! It connected immediately via my computer's BT, without using the dongle that is under the cover. It also has a 2.4 WiFi connection, but I didn't try it because the computer (Win 11 Pro) recognized it right away by pressing the connection button on the top side, behind the roller, and I didn't bother further. If you hold down the roller, it opens the option for scroll just by moving the mouse, and if you press the connection button (behind the roller as I mentioned), it disables the cursor and the green light blinks. Pressing it again returns it to normal use. Of course, it has an on/off switch on the base for battery saving when not in use. Extremely ergonomic for right-handed users, silent, fits perfectly in my hand, not suitable for left-handed users due to its design (even though it is mentioned as such in its features), it has a textured protrusion for thumb support, it is just the right height so you don’t lift your wrist too much and have tendon issues. On the side, there are two additional buttons, the front one for Next and the back one for Previous, I would have liked them a little bit more forward but it's good that they exist and you get used to them. Note: it takes 1 AA battery and not AAA like most. Purchase price €12.10, it's worth even €20!

EDIT: Almost 3 months later, it is flawless! It has some disconnections (maybe because I haven't used my own adapter) but they are resolved instantly by pressing the button twice (blue and then green again), it hasn’t caused me the slightest problem. Also, it notifies you that the battery is nearing the end with the green light blinking quite a bit before it runs out, which is also important because it doesn't "leave you hanging."

P.S.: Honestly, anything I have bought from Ugreen has been flawless.