ELECOM Official Hard EVA Travel Protection Storage Case Replacement for DEFT PRO, Wired/Wireless/Bluetooth Finger-Operated Trackball Mouse, 8-Button, Ergonomic Design - Case Only (BMA-DPT1BK)

These reviews seem to cover several models of Elecom trackballs - this review is specifically for the DEFT Pro model M-DPT1MR (middle size, between small blue-ball and the "Huge").I have tried several trackballs from several manufacturers, trying to find a decent replacement for my failing Microsoft Trackball Explorer (MTSE). The M-DPT1MR is the closest substitute I have found yet.Although the basic shape does not fit my hand quite as well as the MTSE, the shape still is close enough to provide much of the same comfortable ergonomic fit. The main difference is the lack of a "landing area" at the wrist end of the trackball. With the M-DPT1MR, your wrist will rest on the table instead of up on the trackball itself. HOWEVER, I have found that using the proper wrist pad makes an acceptable substitute, positioning my wrist/palm in a very similar position as on the MSTE (see my comparison photo). The M-DPT1MR looks smaller in the photo, but with the extension of the wrist pad, the hand position is very similar.From the photo, the M-DPT1MR ball looks much smaller than the ball of the MSTE, but the measured diameters are very similar (44mm vs 46mm, respectively). I do not notice any difference due to ball size during usage. Ball operation is very smooth.The center and right button placement is not quite as comfortable as the MSTE - the buttons are a bit too close to the ball, and a bit smaller than the MSTE's. But, I have been able to adapt after using the M-DPT1MR for a while. Not too hard a transition.As other reviews have noted, the scroll wheel has a noticeable "clicking" or notched feel. I personally do not have an issue with this - I only really notice it when scrolling long pages quickly, but even then it is not too bad. Seems to smooth out over time. The wheel's click operation is a bit stiffer than the MSTE, but again surmountable, at least for me. The main left-click button seems perfectly natural for me.The Elecom Mouse Assistant software seems to provide all the control I need, for speeds, inertial momentum, and button assignments. I could map the buttons just as I had done for the MSTE. I like the extra buttons for custom mapping, but frankly have not used them much so far.I do wish it was easier to find an English version of the user's manual - it does not come in the packaging, nor is there a clue about where to find it. Unfortunately, Amazon does not allow me to try to help by posting the links here.All in all, so far I have been quite satisfied with the M-DPT1MR. For many people, it may certainly be a reasonable alternative for the MS Trackball Explorer.

i've dealt with carpal tunnel for years, and have used trackballs exclusively for over 15 years. I've used Kensington, Logitech, Nulea... but this is my first Elecom Trackball Mouse. Right now after about a week, this is -very- close to being my favorite so far, with a couple minor points.PROS-Quality plastics and packaging: mine came in a nice presentation box with a gatefold for details about the mouse on the inside of the front cover. Everything inside is well protected in a plastic shell.Overall feel: the plastics are not rubberized, thank goodness! They always break down and deteriorate, so having a nice matte textured plastic to start with is great. Each button is curved to be ergonomic.Good software customization: the Deft Pro has 11 buttons/functions that can be tailored using the Assistant software available on the Elecom USA website. I also tried on macOS the app USB Overdrive which worked well also.Connections: this offers you tons of options: Bluetooth, Wireless Dongle or wired micro-USB. I chose the wired micro-USB since sometimes when I'm mucking around in macOS Terminal, I need a mouse that doesn't need a driver to work with. Since Terminal is accessed before boot completes, a wired connection is the only way to get mouse access.Sensitivity: you have a choice between 500/1000/1500 dpi, and if you are using Bluetooth or Wireless, you can change the sampling rate sensitivity from Low to High, at the expense of the single AA battery life.CONSActual hand grip: the Deft Pro is a bulky design; think of gripping a medium grapefruit or softball, and you are a bit bigger than the actual Deft Pro. Your fingers rest naturally over the buttons and scrollwheel, but it feels larger than some of the other trackballs I've used.Trackball feel: it took about three days of use before the 34mm trackball "freed" itself... all of a sudden, it felt like a surface coating rubbed off and movement was a lot freer. I've read other comments about the bearings for Elecom devices; I've changed out sapphire bearings on my Kensington trackball, and it's a pain. Doable, worth the effort, but a pain. I hope the bearings keep running smooth.Instructions: inside the box is a very detailed Japanese paper manual... if you need one in English, go the Elecom USA website to download the English/multi-language PDF version. You can find the Assistant software on the site as well.If I had to change anything on this Elecom Deft Pro, I'd reduce the overall height about 3mm and for me, that would be perfect. For now, I'm using a low wrist rest to "lift" my wrist higher to accommodate the height. When you've had carpal tunnel, you learn to adjust for your specific needs, so I'm not blaming Elecom here.As a wired trackball, and with custom acceleration and sensitivity settings, this runs great. I just wish the overall shape profile was a wee bit different. That said this is over-engineered and I look forward to using it for a long time to come.