The Finalmouse UltralightX is a lightweight, wireless gaming mouse. It has a symmetrically shaped body with honeycomb-shaped cutouts that help reduce the overall weight. The body is made of carbon fiber composite, which Finalmouse advertises has a better strength-to-weight ratio than either plastic or magnesium alloy. This mouse uses PixArt's flagship 3395 sensor and supports a maximum wireless polling rate of 8000Hz.
You can buy the Finalmouse UltralightX in several different sizes. We bought and tested the medium-sized (Lion) variant. Smaller (Cheetah) and larger (Tiger) size variants are also available. For more details, see the Differences Between Variants section.
Our Verdict
The Finalmouse UltralightX is acceptable for work but isn't designed explicitly designed with this usage in mind. That said, it's very lightweight and has a comfortable symmetrical shape. Unfortunately, while you can connect to it wirelessly with its USB receiver, it doesn't support Bluetooth or multi-device pairing. Also, while it has a web-based configurator, you can't remap buttons without third-party software. Lastly, the scroll wheel feels cheap and lacks helpful productivity features like L/R tilt inputs and free-scrolling.
- Connects wirelessly with its 2.4Ghz receiver.
- Remarkably lightweight; less fatiguing to use for long stretches compared to heavier productivity mice.
- Carbon fiber body is noticeably flexible.
- Left-and right-click buttons feel slightly mushy.
- The scroll wheel feels somewhat cheap and its coating isn't very grippy. Additionally, you can unintentionally actuate the scroll wheel button by pushing the wheel to the right.
- Can't reprogram buttons without third party software.
- Doesn't support Bluetooth; no multi-device pairing.
- Scroll wheel lacks a free-scrolling mode and L/R tilt inputs.
The Finalmouse UltralightX is a superb FPS gaming mouse. Its carbon fiber composite body makes it remarkably lightweight and easy to move quickly and accurately. It also has incredibly low and consistent click latency and outstanding all-around sensor performance that's more than suitable for gaming at any competitive level. Unfortunately, it also suffers from some build quality issues. The left-and right-click buttons feel mushy, and the scroll wheel feels cheap. Additionally, although the body is very strong, it's also quite flexible, and if you apply pressure to the underside, you can separate the top and bottom pieces of the chassis. While these issues are noticeable, we don't expect them to impact your in-game performance negatively. For more details about these issues, see the Build Quality section below.
- Remarkably lightweight.
Maximum wireless polling rate of 8000Hz.
- Incredibly low and consistent click latency performance.
- Outstanding all-around sensor latency and accuracy.
- Carbon fiber body is noticeably flexible.
- Left-and right-click buttons feel slightly mushy.
- The scroll wheel feels somewhat cheap and its coating isn't very grippy. Additionally, you can unintentionally actuate the scroll wheel button by pushing the wheel to the right.
The Finalmouse UltralightX is adequate for MMO gaming but has fewer side buttons than a dedicated MMO gaming mouse, and you can't remap buttons without third-party software. That said, it's exceptionally lightweight and has incredibly low and consistent click latency and outstanding sensor performance, providing an exceptionally responsive-feeling in-game experience.
- Remarkably lightweight.
- Incredibly low and consistent click latency performance.
- Outstanding all-around sensor latency and accuracy.
- Carbon fiber body is noticeably flexible.
- Left-and right-click buttons feel slightly mushy.
- The scroll wheel feels somewhat cheap and its coating isn't very grippy. Additionally, you can unintentionally actuate the scroll wheel button by pushing the wheel to the right.
- Significantly fewer side buttons compared to dedicated MMO gaming mice.
The Finalmouse UltralightX delivers fantastic raw performance. Its click latency is incredibly low, and the sensor latency and accuracy are outstanding. This mouse also supports a maximum wireless polling rate of 8000Hz, delivering slightly better and more consistent overall performance over a standard 1000Hz polling rate. However, using higher polling rates also requires considerable CPU resources and consumes battery power much more quickly.
Maximum wireless polling rate of 8000Hz.
- Incredibly low and consistent click latency performance.
- Outstanding all-around sensor latency and accuracy.
Changelog
- Updated Mar 10, 2026: We've converted this review to Test Bench 1.5.2. This update removes the Delay To Start Of Movement and Delay To End Of Movement measurements from the Sensor Latency test. See our full 1.5.2 changelog for details.
- Updated Aug 19, 2025: We've converted this review to Test Bench 1.5.1. This update removes less relevant or redundant elements, including several videos. We've also adjusted our Sensor Latency testing, resulting in minor score changes. See our full 1.5.1 changelog for details.
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Updated Jan 23, 2025:
We've added a link to the newly-reviewed Finalmouse UltralightX Competition in the Hand Size Recommendation section.
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Updated Jan 20, 2025:
We've retested this mouse's Click Latency and Sensor Latency performance after the most recent round of firmware updates, which increased the maximum polling rate to 8000Hz. We've updated our scoring and included new text in several places.
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Differences Between Sizes And Variants
The Finalmouse UltralightX is available in two color options and three size variants. The color options include a gold and black colorway called Guardian and a blue and black colorway called Phantom. The three sizes available are small (Cheetah), medium (Lion), and large (Tiger).
We bought and tested the medium (Lion) variant in the Phantom colorway. You can see the label for the unit we bought and tested here. This image is mostly obscured as the label is inside the honeycomb shell. The model number on our unit is S/N: MA233717514.
We expect all size variants to perform similarly, and we expect most of our tests will broadly apply to all sizes except for obvious tests like Shape and Weight.
| Name | Color Options | Advertised Weight | Advertised Dimensions |
| UltralightX (Cheetah/Small) | Guardian, Phantom | 31 g | 115.6mm Length x 54.1mm Grip Width x 35.2mm Height |
| UltralightX (Lion/Medium) | Guardian, Phantom | 35 g | 121.3mm Length x 56.8mm Grip Width x 37mm Height |
| UltralightX (Tiger/Large) | Guardian, Phantom | 37 g | 126mm Length x 59mm Grip Width x 38.4mm Height |
Note: The Finalmouse UltralightX unit we purchased is a Batch 1 production model. Finalmouse has since released Batch 2 models. Finalmouse advertises that these newer models have several build quality revisions. You can read Finalmouse's statement concerning these differences here.
If you have this mouse and want to share your experiences with us, we'd love to hear from you in the forums.
Popular Mouse Comparisons
The Finalmouse UltralightX shares the same honeycombed, symmetrical shape as Finalmouse's previous Starlight-12 Medium. Still, it has an upgraded sensor and is the first Finalmouse release to support polling rate settings over 1000Hz. Additionally, this mouse's body is made of a carbon fiber composite, which Finalmouse advertises as having a significantly better strength-to-weight ratio compared to ABS plastic used by most gaming mice, as well as the magnesium alloy material used in the body of the Starlight-12. Until now, gaming mice with carbon fiber bodies were limited to much more niche and expensive models such as the Zaunkoenig M2K.
The UltralightX also marks the first mouse Finalmouse has committed to keeping in continuous production. It's noteworthy as Finalmouse's previous releases have been limited quantity drops, often making them difficult to buy without resorting to the reseller market. That said, at the time of writing, the size of the production batches for the UltralightX remains small related to the demand, and all models are currently sold out. If you're interested in this mouse, you may need to check back often and buy this mouse soon after a new production batch is made available. You can reference the Finalmouse Twitter feed for updates on new batch releases here.
For more recommendations, see our picks for the best lightweight mouse, the best FPS mouse, and the best wireless gaming mouse.
The Razer Viper V3 Pro and the Finalmouse UltralightX are lightweight, high-performance, wireless gaming mice. The Finalmouse is significantly lighter than the Razer thanks to its carbon-composite shell with honeycomb-shaped cutouts. However, the Razer has superior build quality and a more conventional design with a solid plastic shell. The two mice perform very similarly overall, but at the time of writing, the Razer supports a higher maximum polling rate of 8000Hz, whereas the Finalmouse's is only 4000Hz.
The Finalmouse ULX Pro Series is an ultra-lightweight gaming mouse based on the Finalmouse UltralightX. The mice share the same sensor, 4000Hz maximum polling rate, and carbon composite body with honeycomb-shaped cutouts. The ULX Pro Series is a limited edition mouse released in different color variants than the UltralightX, while Finalmouse has committed to keeping the latter in continuous production.
The WLmouse Beast X Max and the Finalmouse UltralightX are high-performance, lightweight gaming mice with cutouts throughout their bodies. The Finalmouse has a carbon fiber composite construction with small honeycomb cutouts, while the WLmouse is made of a magnesium alloy with large trapezoidal cutouts. While the two mice have comparably outstanding raw gaming performance, the WLmouse has better build quality with a more solid construction that doesn't flex as much but is slightly heavier.
The Finalmouse UltralightX (Medium/Lion size variant) and the WLmouse Beast X are both ultra-lightweight wireless gaming mice with virtually the same symmetrical shape. The Finalmouse is made of carbon fiber composite and has slightly better overall raw gaming performance. Unfortunately, we reviewed an early batch model with build quality issues. Reports from the community suggest that many of these issues have been addressed in later batches. We expect current models to be roughly comparable to the WLmouse regarding build quality. Comparatively, the WLmouse has a magnesium alloy body and is slightly more lightweight. Additionally, the WLmouse is more readily available as it has been continuously in stock at the time of writing, while the Finalmouse has only been released in small staggered batches.
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