Review on Perixx PERIPRO-303 X4A Trackball With 1.34-Inch Replacement Ball For Perimice And M570 - 4-In-1 Multi-Color Trackball In Red, Purple, Pink, And Lavender With Stylish Storage Box by Mike Hernandez

I've got a few trackballs, and I swapped out the ball for some Perixx ones and for sure this has to be the first time blue balls were a good thing to have. I have a few color balls, blue, purple, red and what have you and these fit great in my Elecom travel track ball. But please keep them out of your mouth - they are big enough it would seem it is easy to choke on these blue balls.For sure a happy purchase and if Perixx makes bigger balls I'll put them in my other track balls be they blue or some other color.