Kensington Expert Wireless Trackball Mouse (K72359WW) Black, 3.5″ x 6.1″ x 8″

Customers find the trackball mouse to be of good quality and appreciate its programmable buttons, with one customer noting it's better than a trackpad. The Bluetooth connectivity and ergonomics receive mixed feedback - while some say the Bluetooth connection works well and find it ergonomic, others report connectivity issues and poor ergonomics. The scroll wheel performance and size also get mixed reviews, with some praising the smooth motion while others say it doesn't roll smoothly and find the ball too large for practical use. Comfort levels vary, with some finding it comfortable to use while others report wrist pain during use.