With the Hati-S2 8K, G-Wolves continues to expand their Hati-S series of mice. Contrary to what one may expect, the "2" doesn't indicate a successor to the regular Hati-S, but rather an even smaller Hati-S, a "Hati-XS" if you will. The Hati-S2 8K ends up being both shorter and lower-profile than the original Hati-S and, by extension, the Hati-S Plus, which is longer but otherwise essentially identical to the Hati-S. While the Hati-S shape has always lent itself well to claw grip, the Hati-S2 8K is particularly suited to an aggressive claw grip, as it retains the width but not the length of the Hati-S, while still providing ample palm support. In terms of weight, the Hati-S2 8K lands well below both the Hati-S Plus ACE or Hati-S Plus 4K, which clocked in at 51 and 46 g, respectively. Despite carrying a 250 mAh battery, the Hati-S2 8K only weighs 34 g, and aside from several slits scattered across, the top shell is solid, and only the bottom is largely open. Much like on previous G-Wolves designs, the PCB has been extended to aid with structural integrity, with remarkable success. Despite the incredibly low weight, my sample of the Hati-S2 8K is solid throughout, without any rattle when shaking, no creaking or flexing of the shell when applying lateral pressure, and the side buttons cannot be actuated by pressing below them, either. Once again, G-Wolves proves that ABS plastic is among the best materials one can use for a mouse, provided the engineering is smart enough to leverage its material properties.

In terms of internals, the Hati-S2 8K is no different from the Hati-R 8K. The main button switches come from Huano and are of the blue transparent shell, pink plunger variety. Generally, these are known to deliver firm and snappy actuation, though on the Hati-S2 8K, button response is slightly marred due to pre-travel verging on high. Though I didn't notice anything during actual use, moderate levels of lateral movement can be provoked. The side buttons are outfitted with surface-mounted Omron switches, which of course limit how satisfying feedback can be. Still, on the forward button, pre and post-travel are very low, whereas the back button exhibits moderate pre-travel, resulting in mushier actuation. For the scroll wheel, G-Wolves has opted for an encoder from TTC, more specifically of the blue/yellow core variety. Tactility is great on this one, as each step is clearly defined, and noise levels are mostly under control. Much like on previous G-Wolves releases, the bottom lacks indents for feet, allowing one to apply feet of non-default sizes and shapes. Aside from the dot feet installed by default, two sets of larger feet are included with the mouse, along with another set of dots. They're all made of pure PTFE, and glide very well.

The similarities in terms of internals to the Hati-R 8K continue with the sensor and MCU, which still are PixArt's PAW3395 and a Nordic nRF52840. However, whereas the Hati-R 8K had been tested on the older 00.00.17 firmware, the Hati-S2 8K has been tested on the more recent 01.00.36 and 01.00.37 firmware versions, which perform slightly differently. Of note is the higher CPI deviation of +3.8%, though this has nothing to do with firmware and rather sensor mounting height. In any case, correcting this is easy. General tracking shows no issues, irrespective of whether MotionSync is enabled or not. In terms of polling, the firmware versions behave the same as well, as not a single poll is missed even at 8000 Hz, and all other rates are perfectly stable, too. Differences emerge when it comes to latency, however. Firmware version 01.00.36 and later have been specifically optimized for battery life, which is why motion delay is slightly higher than before now, as instead of the 1.0 ms lead the Hati-R 8K had over the Logitech G403 (control subject) at 4000 Hz in wireless operation, the Hati-S2 8K on the more recent firmware is only ahead by 0.7 ms. Much like before, 8000 Hz posts worse numbers presumably due to a larger buffer for retries being used. Notably, the firmware versions behave differently in terms of motion delay over time, as on the older firmware, the Hati-R 8K was ahead of the G403 consistently throughout the entire motion, whereas on the newer firmware, the Hati-S2 8K is initially behind the G403, and only gets ahead after first the first few milliseconds of the motion. In practice, these differences are miniscule of course, and for those who value raw performance above all, using the 00.00.17 firmware version is always an option. For everyone else, the improved battery life afforded by the newer firmware will likely be appreciated, however.

In terms of click latency, differences exist between the 00.00.17 and 01.00.36 firmware versions on the one side and the 01.00.37 firmware version on the other. With the former, the Hati-S2 8K will average no more than 0.3 ms in wireless operation regardless of polling rate setting, provided debounce time is set to 0 ms. Setting debounce time to the lowest value has no immediate downsides as long as there is no double-clicking, as a slam-click prevention algorithm is present, adding additional debounce whenever the mouse has been lifted, such that no accidental button actuation occurs when resetting the mouse. However, this algorithm is flawed on the former group of firmware, in that the first click after lift-off will have the full ~16 ms added applied, even when the mouse has already been landed again. Firmware version 01.00.37 fixes that, but also increases click latency to 0.5 ms in the process. This is likely unintentional, but even if it weren't, marginally higher average latency is always better than inconsistency in my book, as is the case with some clicks having upwards of 16 ms of latency, just because the mouse has been lifted right before. Once again, the choice is ultimately given to the user here.

As mentioned before, the 01.00.36 firmware improves battery life, and from what I can tell, considerably so. While the percentage-based battery life indicator found in the software isn't particularly reliable, it is good enough to give a rough indication at least. After two hours of usage at 8000 Hz and another three at 1000 Hz, it stood at 90%, which is why G-Wolves's cited value of 80 hours at 1000 Hz appears more than plausible. Charging isn't all that speedy on the Hati-S2 8K, but decent enough, though playing while charging won't be an option with the included cables anyway. The first one isn't all that flexible to begin with, but more importantly seriously short at 1.10 m, whereas the second one is a bit longer at 1.45 m yet even stiffer. An obvious solution would be to include a stiff and well-shielded cable for extension purposes and another one that is long and flexible for charging. Either way, it is best to keep the Hati-S2 8K charged at all times to minimize forced downtime. In that regard, it is also important to remember to only charge the mouse with the power switch set to "on," as charging speed will be abysmal otherwise.

Much like on the Hati-R 8K, configuration on the Hati-S2 8K is done through a web driver. Due to using WebHID, this web driver will only work in Chromium-based browsers such as Chromium or Edge. Hence, for those not already using these browsers, being directed towards a web driver requires installing an additional browser, which of course comes with its own resource footprint, much like a regular peripheral software would. In addition, if G-Wolves were to go defunct, or decide to no longer host the web driver, configuration would become impossible, as a local copy unfortunately won't work. This is doubly problematic in that the Hati-S2 8K doesn't even have a CPI button, so even something basic as changing CPI requires a configuration driver. As such, I consider the web driver a step back compared to the previous standalone application featured on earlier G-Wolves mice, and would welcome if G-Wolves would also release a desktop version of their web driver in the future. As for the driver itself, I couldn't find any bugs, and all the relevant options are present. The only minor issue is that setting changes can still be made after the mouse has entered sleep mode, yet won't be applied, which isn't communicated through the UI. An additional oddity is that any adjustment to the debounce settings will only take effect after the mouse has been lifted and reset once.

At $139.00, the Hati-S2 8K is offered for $10 less than the Hati-R 8K, which is remarkable in that the internals are one and the same, and only the shape differs. Obviously, the Hati-S2 8K is still far removed from bargain territory, but given the quality and performance put forward by the Hati-S2 8K, the pricing isn't completely unreasonable at least. At 34 g, the Hati-S2 8K is also among the lightest full-size mice around, easily besting recent releases such as the Hitscan Hyperlight, SCYROX V8, or Arbiter Studio AKITSU in this regard, and its shape is rather unique, though at the same time, after-sales support always has a question mark attached to it with G-Wolves. Those who can deal with that, however, will find a great mouse in the Hati-S2 8K, and one worthy of our Recommended award.