i thought this is a good deal. the cheapest its ever been on amazon and half the price of the next seller.
this will help you troll hduk for longer without the neck ache you get from the normal mouse
Kensington ExpertMouse Optical Wired USB Trackball for PC and Mac
The Expert Mouse employs Kensington's DiamondEye optical technology for smooth, precise cursor movement. Surrounding the ball, our award-winning Scroll Ring lets you scan up and down the screen with complete ease. The height of comfort, the Expert Mouse even comes with a soft wrist rest right in the box! In addition to all these great features, you'll find the same large ball, exceptional control, four programmable buttons and ease-of-use that have set the standard in trackballs for more than 15 years. DiamondEye Optical Technology Optical sensing provides precise tracking for accuracy while moving the cursor around the screen.