Sanwa Supply Bluetooth trackball (silent, 5 buttons, index finger/middle finger operation type) MA-BTTB183BK Mice - Newegg.com
Amazon.com: Wireless Trackball Mouse, Rechargeable Ergonomic Design, Index Finger Control with 5 Adjustable DPI, 3 Device Connection (Bluetooth or USB), Compatible for PC, Laptop, iPad, Mac, Windows, Android : Electronics
Amazon.com: YUMQUA Y-10L Finger Handheld Trackball Mouse with Laser Pointer, 2.4G USB Wireless Trackball Mouse for Laptop Computer PC Black : Electronics