ProtoArc Wireless Trackball Mouse, EM01 NL Ergonomic Bluetooth Rollerball Thumb Rechargeable Computer Laptop Mouse, Adjustable Angle & 3 Device Connection for PC, Mac, Windows-Red Ball

Customers find this trackball mouse to be a high-quality ergonomic device with adjustable tilt that comfortably fits the hand. The mouse offers easy Bluetooth connectivity to multiple devices, and customers consider it excellent value for money. The responsiveness receives mixed feedback - while the trackball movements are very smooth, some report it stops working after a few seconds. The button responsiveness and tactile feel also get mixed reviews, with some finding them responsive and nice for bigger hands, while others note the buttons are too sensitive.