In our review, the MM310 turned out to be a very solid budget offering from Cooler Master. The MM311 is essentially the same mouse, just driven by a single AA-battery instead of wired. Accordingly, the MM311 shares both the strengths and weaknesses of its wired sibling.

As with the MM310, the weight of the MM311 is impressive. Without the battery, the MM311 weighs no more than 52 g, which is very similar to the MM310. With an AA-battery, it'll weigh around 75 g, which is quite a bit more than many wireless mice running on an internal battery weigh these days, but still superior to other AA-battery driven mice such as the similarly sized ASUS TUF M4 Wireless at 85 g. By using a Lithium AAA-battery with an adapter, the MM311 could be made to weigh as little as 62 g. Even the much smaller Razer Orochi V2 weighs more with this configuration. Accordingly, even outside of its price bracket, the MM311 manages to come out on top of the competition. That said, when using the default AA-battery, the MM311 can feel rather back-heavy by virtue of being so light to begin with. Furthermore, from a usability perspective the battery cover isn't optimal as getting it off can be harder than expected.

In terms of build quality, the MM311 is just as solid as the wired MM310. On my copy, there isn't any rattle when shaking, no creaking or flexing when applying pressure, and while the side buttons can be actuated by squeezing the sides, doing so requires an absurd amount of force. Kailh GM 4.0 switches are used for the main buttons, which provide a firm and snappy response without being overly heavy, while the other buttons are outfitted with Huano (green) switches, both of which are switch choices rarely encountered in this price bracket. Some pre-travel and uneven actuation on the back button aside, the side buttons are quite pleasing. The scroll wheel once again is using an encoder from Kailh, which scores with low noise levels and above average tactility. Durability may be a concern, however, as the same rubber-ring design previously seen on the MM731 is employed, which proved to be potentially flawed. The feet are of the same material as the ones used on the MM731, which is why glide is very good.

Being equipped with PixArt's aging PMW3325, which has primarily been conceived for wired use, the MM311 is strictly limited in terms of what performance can be achieved. This is relevant in that Cooler Master did go the extra mile by including a wireless extender in the box to ensure the best possible connection, which is pretty much unheard of for a $40 mouse. Still, there is only so much one can do to make a 3325 perform well in a wireless mouse, though Cooler Master at least managed to do a better job than Corsair did on their Katar Pro Wireless, which performed very poorly. The main limitations of the PMW3325 are power-saving and malfunction speed. In order to squeeze out as much battery life as possible, applying aggressive power-saving is a necessity on the 3325. Compared to the Katar Pro Wireless, Cooler Master found a better balance in this regard, as the sensor doesn't enter a rest state as quickly, and waking from it doesn't take as long, either. Waking from the actual sleep mode does take longer than on a typical mouse using a 3370 sensor, but considering that the time after which said mode is entered is user-configurable, this can be adjusted if so desired. On paper, the 3325 is rated for a malfunction speed of just 2.54 m/s, which is well below of what could be considered sufficient no matter the use case. On the MM311, I've only been able to get the sensor to malfunction at a speed of around 3.5 m/s, which is well above specifications but still falling short of a good level. Still, those using a higher sensitivity or playing games that don't require as much mouse movement may find the MM311 to work well enough.

In terms of performance, the MM311 isn't top tier, but quite decent nonetheless. Motion delay sits at roughly 4 ms, which is a bit more than what the MM731 was able to muster while using a much better sensor and MCU. Aside from minor outliers, polling is stable throughout, and general tracking likewise is fine apart from the occasional outlier. Much like on the MM310, CPI deviation is significant and far from consistent, which, coupled with CPI adjustment being limited to increments of 100, can make it difficult to get the exact CPI step one desires. The biggest issue by far, however, is the lift-off distance. Even at a height of 3 DVDs, the sensor still keeps tracking, and only stops doing so at a height of 4 DVDs. Considering that LOD isn't adjustable due to a sensor limitation, this is a major issue for anyone valuing low LOD. As a workaround, one can try covering part of the sensor with tape to lower LOD, but this of course isn't exactly optimal.

Click latency, on the other hand, is surprisingly stellar on the MM310. When using the lowest button response time setting, click latency sits at just 1.5 ms, edging out even Logitech's G Pro Superlight X. An undesired side effect of this incredibly low latency is frequent slam-clicking, which describes inadvertent button actuation when resetting the mouse. At the 1 ms setting, slam-clicking happens a lot, at 2 ms, much more rarely, and at 3 ms, it no longer happens at all. Since the setting scales linearly, getting rid of slam-clicking entirely thus only comes with a 2 ms penalty, which results in a still highly competitive latency. Adjusting button response time is only possible in Cooler Master's MasterPlus software, which is pleasantly bug-free, but does have a pronounced appetite for RAM in particular. That said, MasterPlus is nowhere near as bad as the likes of ASUS Armoury Crate or Corsair iCUE, and owing to on-board memory support, keeping the software installed is but an option.

Overall, the MM311 does have its flaws, but for $40, beggars can't be choosers, and it no doubt performs better overall than the identically priced Katar Pro Wireless, which has good buttons, more aggressive power-saving, unstable polling at 1000 Hz, similarly high motion delay, no wireless extender, and a higher weight. The SteelSeries Rival 3 Wireless too lacks a wireless extender, performs only marginally better, weighs significantly more, but has good buttons and Bluetooth, for $49.99. Lastly, the ASUS TUF M4 Wireless also has good buttons, much better performance, and Bluetooth, but no wireless extender and the Armoury Crate burden, for $59.99. Accordingly, the MM311 earns our Budget award.