You don’t have to settle for your uncomfortable computer mouse. In fact, you can use the Logitech M570 Wireless Trackball Mouse instead. This gadget has a shape that makes it even more comfortable for all-day use. That’s because it includes a built-in trackball that stays in one place and helps stabilize your hand and arm. Additionally, this wireless mouse uses a unifying receiver that you plug into your computer for easy connectivity. Surprisingly, all the M570 needs is a single..