SANWA 55mm Trackball, 2.17in Replacement Ball for Kensington SlimBlade, SlimBlade Pro, Expert Mouse, Perixx Keyboard Periboard-522/322, and Other Compatible Mouse, Glossy Red

Perfect replacement for my Logitech M575 trackball. I saw warnings that the ball was a bit small, but it fit my trackball quite well. Smooth as silk. Over the years, I have had many Logitech trackballs. Each of them failed in the same way: the ball wore out. I just ordered two more to revive the two M575's sitting on the shelf.

Don't walk, run for this thing! Works with both my m575s and MX Ergo S. I saw a review talking about how it worked better than the original ball, and while I believed it, I was skeptical it would actually make much of a difference. Now I'm considering replacing the one in my other track ball with one of these! It is a much smoother experience both physically and virtually. It's much more accurate than the original. Plus... it's cheap! I have no worries about this thing lasting a long time—it is very high quality.

This trackball fits perfectly in the MX Ergo mouse and it looks really nice. It feels just like the original trackball.

Fit my odd sized mouse perfectly and works like a charm. I lost the original one. It is a less common mouse trackball size and so thankful I was able to find one at such a reasonable price. Was grateful for the speedy shipping I could not use my computer without a mouse. The ball glides smoothly.

Exactly as expected and what I needed!

Delivered in a timely manner. Fits and works perfectly.

Works well with the M575 logitech mouse. The red color ball is tracked better than the blue color ball. The blue color seems harder to read and sometimes the pointer would move less distance than expected. Recommend not getting the blue color for the M575. Red works perfectly.

I don't remember it EVER being this smooth! I've had the MX Ergo for a few years now and it's always been a good trackball, but this new ball is amazing! I keep pretty good care of the original trackball. I take it out every once in a while, wipe it down, clean the bearings that hold it, but a soon as put this new one in, I thought I had done something wrong... there was literally ZERO resistance, no noise, no "scratchy" feel and it is very accurate. It's so smooth, I can barely feel it under my thumb. If I ever have to replace my MX ergo, I WILL be replacing the ball right away with another one of these.

Seems a little lighter than other brand 55mm ones, but it's smooth and I see no faults or defects.

Perfect replacement, fitted no issues, as good as the original. Replaced the ball on my Logitech MX Trackball

I accidently dropped my Kensington TB550 Trackball on the road and a large chip came off the ball. I did not see a replacement ball on Amazon for my particular device, but I measured the ball and it looked like this one would fit and it did. Perfect fit and works great.

My Logitech M575 was starting to get a little rough and scratchy; turns out that there were some barely even visible scsuffs/rough spots on the ball (probably from repeatedly being dropped lol), that were just enough to sort of catch on a bearing when that part of the ball passed over one. I couldn't find my old Marble+ with it's classic red speckled ball, so I ordered one of these. Specifically in purple, which ended up looking pretty good if you ask me. Very deep, kind of dark purple, with some fine sparkle to it. Was very surprised to find just how much smoother a different ball could make this mouse feel. It's almost *too* smooth, though I quickly got used to it. I do like the [extremely subtle] bit of "grit" that the original Logitech balls have, which just feels like it keeps the ball from moving when you're just resting your thumb on it, but don't intend to move the cursor, but those balls look and feel completely smooth in the hand, so I always wondered if that grit I described was all in my head... but after popping this thing in, I'm fairly certain I wasn't imagining it. It feels like it's floating on lubricated roller bearings in comparison to the original. Even better: it actually feels like it fits *better* than my stock Logitech ball. Not that that was a bad fit, but when switching directions, you'd occasionally hear a little tick as the ball's weight shifted from one bearing to the one on the other side. This doesn't do that. Kinda wild. Anyway, it's a ball, and apparently moreso than the perfectly adequate one I had before!? 😅

Awesome ball . Way smoother than original . Very happy .