I ordered this to replace my ball that was lost when I dropped my phone. The replacement ball did not work very well. It took forever for it to respond to motion in any direction (up, down, left, or right), and if it did respond it would move just one space/item and then you are stuck again trying to get it to move more. Needless to say I ended up purchasing a new Blackberry Curve, this time with the touch pad instead of the trackball.