Perixx Peripro-304 Trackball, 2.17 Inch Large Replacement Ball for Periboard and Kensington Mouse, Glossy Red, 18033

Works just as good as an original and very reasonable price. I accidentally dropped the original and it got a small chip in it. I actually like the slightly darker red color. People complaining about it not rolling smoothly, add one tiny drop of high-end machine oil and rub it with your hands.... It will roll insanely smooth like the original. I highly recommend.

Perfect replacement for my wired Kensington expert gray ball. Smoother and quieter without impact to performance. No one else makes a compatible backup so I picked it up as a preemptive spare in case Perixx stops making these.Perfect fit, no issues with weird or sticky coating and didn’t need to rinse off like someone else in the comments had to do.Only con was that it was packaged in a paper bubble Mailer by the manufacturer and then packaged in a plastic bubble mailer by Amazon. Came out unscathed but for something that needs to be perfect to work, you’d think a box would be warranted.My gray ball has survived a few falls already relatively unscathed, so I really picked this up only as a back up since it was so cheap on sale.It’s the part most likely to fail and cheaper than to replace the whole thing.But now I prefer it as my primary. Color is nice too, like a grape-cherry jolly rancher.

It’s a great replacement for Kensington Expert. Not a fan of the color as it’s slightly more magenta than the Kensington Expert ball, but it works well and is worth the money.

If you ever dropped the ball from a Kensington trackball, then you know how aggravating even small blemishes can be when using the trackball. These balls are sized nearly identically to the original Kensington SlimBlade balls and work as well as original. The red color is slightly lighter than original but not much. The only thing I would recommend is giving the ball a good cleaning with some form of detergent (I used hand soap) before use; straight from the package, there is some sort of light coating that does not allow the balls to work as well as they should. Otherwise, I am thrilled to be able to continue using my trackballs without having to buy a completely new unit. That would be akin to stepping on one of these... Trippin' balls, that it.

I recently bought a Kensington SlimBlade trackball mouse and having done my research I knew that Kensington refuse to supply replacement trackballs when they get damaged (at least here in UK), forcing you to buy a whole new mouse. I also knew that the Peripro-304 was the only replacement on the market that fits, but they've been out of stock for quite a long time (presumably due to Covid, etc).Anyway, one day I randomly decided to check if they'd come back in stock and sure enough Amazon had 8 them. I ordered one straight away and a few days later it was in the UK and in my hands. I tried it out and it works just as well as the OEM item, it not better. It's not quite as attractive as the original ball as it doesn't have that same metallic effect in the paint, but honestly it's a very subtle difference (and really, who cares?!).My Peripro-304 is now safely stashed away in the cupboard, waiting for the inevitable time when either myself, or more likely my kids, drop the OEM ball and scratch it, rendering it useless!So overall this item comes highly recommended, and if you have the spare cash I'd recommend picking one up BEFORE you need it. After all, if you use your mouse for work (as I do), even waiting a day or two for a replacement might be really inconvenient, and that's obviously assuming that they haven't sold out again!TIP: Before using it, make sure you clean both the ball and the socket on the mouse until they are completely free of dirt and dust. Then spend 30 seconds lubricating the ball by rolling it against your face and between the palms of your hands, allowing it to pick up a light coating of your natural skin oils. After doing that you should find the ball operates nice and smoothly. Repeat this process at least monthly to keep your trackball working optimally. This tip obviously applies to the OEM ball as well.

I purchased this as a backup trackball for my Kensington Slimblade Pro EQ (white/silver model). Despite the item description and experience of other reviewers, it does not work well with my particular unit. It's possible Kensington's manufacturing tolerances have changed, but this particular Perixx ball was extremely rough out of the package and gave a scraping sensation like sandpaper. I lightly washed the trackball per the recommendation of another reviewer which did improve it's performance slightly, but sadly felt no where near as smooth as the stock ball. My guess is the trackball is a micron or two out of spec, making it ever so slightly too large. In terms of weight and size, they feel identical in the hand. I'm aware that sometimes balls have a break-in period, but compared to a previous replacement ball from Perixx (see photo), this is night and day. The smaller ball moved like butter out of the package, and despite having the same "glossy red" designation, you can clearly see is an entirely different color. This 55mm ball is a dull maroon. Nowhere near red to my eyes, and covered in micro scratches and abrasions out of the box due to the lack of protective plastic or paper. For $30, I expected a lot more. All that to say, the sensor does seem to track better with this ball than the stock ball, hence the two stars. If it had moved smoothly, I would have accepted the other issues.

I've bought several Kensington Expert Mouses over the years and I always replace the trackball with one of these. It's got a nice, deep red color; it's almost purple. It feels just like the original ball, but looks nicer.