Review on Perixx Periboard-522 Wired Trackball Mechanical Keyboard With 2.17 Inch Built-In Pointing And Scrolling Feature, US English Layout by Billy Stull

I purchased this "Perixx Peripro-304 Trackball, 2.17 Inch Large Replacement Ball" specifically to use in my, "Kensington Expert Trackball Mouse (K64325)". The reason is that I simply wanted a more colorful ball to replace the original charcoal colored ball that came in the Kensington mouse. I received the new red ball, and it very easily fit. The new one simply drops in. And the new red ball is functionally OK. But I have one reservation.The new red Perixx Peripro-304 size is listed as 2.17 inches. In later text it is also listed as 2.16 inches. The original, replaced Kensington ball is listed as 55mm which is 2.16535 inches. That is, the replacement ball is microscopically different in size from the original Kensington. The bottom line . the new red ball, fits relatively well. It is very well manufactured and well polished. The difference is that new red ball does NOT ROLL QUIET AS EASILY. It does roll adequately. But one can feel the slightly reduced freedom of the roll with the new ball. I have seen other reviews, and the consensus of purchasers seem happy. For me that small difference in size and feel of roll is a disappointment. I have used it enough to know that the small amount of drag using the new red replacement ball has been enough to cause me to give it up and go back to the original Kensington gray ball. A disappointment, and ultimately a waste of money. It is definitely a workable replacement. But not a perfect replacement.