The Finalmouse Starlight-12 Poseidon Small is an ultra-lightweight wireless gaming mouse and a continuation of the Finalmouse Starlight-12 lineup. Weighing under 45g, it's among the lightest gaming mice available to date. It has the same symmetrical shape and honeycomb magnesium alloy shell found on the previous versions, but the major difference is that it comes in a blue colorway. Finalmouse also claims to have made some minor build-quality tweaks, and like the rest of the Starlight-12 lineup, this mouse uses the company's latest firmware to improve the wireless connection. As Finalmouse releases their mice in limited drops, the only way to purchase this mouse is through a third-party seller unless the company does another drop in the future.
Our Verdict
The Finalmouse Starlight-12 Poseidon Small is an adequate mouse for office use. It feels very solidly built, and it's comfortable to use if you have small or medium-sized hands. It connects wirelessly using a USB receiver, or you can use it in a wired mode with its flexible cable. Unfortunately, its scroll wheel lacks a free-scrolling mode and L/R tilt inputs, and the mouse lacks Bluetooth support. Also, it doesn't have companion software to remap buttons or customize any settings.
- Incredible build quality.
- Extremely lightweight.
- High-quality feet and cable don't cause drag on desks or mousepads.
- Scroll wheel lacks a free scrolling mode and L/R tilt inputs.
- No companion software for customization.
- Too small for large and extra-large hands to use comfortably.
- No storage compartment for USB receiver.
The Finalmouse Starlight-12 Poseidon Small is an excellent mouse for FPS gaming. Thanks to its magnesium alloy shell, it feels very well-built and is extremely lightweight. The high-quality feet and cable offer a drag-free gliding experience on mousepads and desks. Performance-wise, it has remarkably low click latency and a very low lift-off distance. It has four CPI presets that you can cycle through using the button behind the scroll wheel, but since there's no companion software, you can't adjust the CPI settings or reprogram any buttons.
- Incredible build quality.
- Remarkably low click latency.
- Extremely lightweight.
- High-quality feet and cable don't cause drag on desks or mousepads.
- No companion software for customization.
- Too small for large and extra-large hands to use comfortably.
- No storage compartment for USB receiver.
The Finalmouse Starlight-12 Poseidon Small is an acceptable MMO gaming mouse. It doesn't have nearly as many side buttons as dedicated MMO mice, and it doesn't have companion software, so you can't remap the side buttons it does have. On the bright side, it does feel very well-built and comfortable to use, and its high-quality feet and cable don't cause drag during use. Also, the click latency is very low. Although you can't adjust the CPI settings precisely, you can cycle through four presets using the button behind the scroll wheel.
- Incredible build quality.
- Remarkably low click latency.
- No companion software for customization.
- Too small for large and extra-large hands to use comfortably.
- No storage compartment for USB receiver.
- No storage compartment for USB receiver.
Changelog
- 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.
- Updated Apr 02, 2024: We've uploaded a new 3D scan, as the previous scan was slightly tilted.
- Updated Jan 10, 2024: We've updated the CPI graph displayed in the Sensor Latency section of this review. Our results remain the same, but these graphs have two new columns with results from the Delay At Half Movement and Delay To End Of Movement tests.
- Updated Oct 02, 2023: We've added text to this review for the new tests added in TBU 1.5.
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Differences Between Sizes And Variants
The Finalmouse Starlight-12 Poseidon Small is only available in one colorway. There's a larger version of this mouse available called the Finalmouse Starlight-12 Poseidon Medium. You can see the label for our unit here.
Popular Mouse Comparisons
The Finalmouse Starlight-12 Poseidon Small is a continuation of the Starlight-12 lineup, and it features a new colorway and some minor tweaks to the manufacturing and quality assurance process. Like the Finalmouse Starlight-12 Phantom that was released earlier, the Poseidon uses Kailh 8.0 switches rather than the Omron switches found on the earlier models of the Starlight. The scroll wheel on this unit is centered and doesn't have the operational issues present on other models. Also, this mouse offers the best performance in terms of click latency if you have the firmware updated to the most recent version. This mouse is among the lightest available on the market currently. However, it's only available through third-party resellers as Finalmouse launches its mice in limited drops.
For more recommendations, see our picks for the lightest mouse, the best wireless gaming mouse, and the best wireless mouse.
The Razer Viper Mini and the Finalmouse Starlight-12 Poseidon Small are both lightweight gaming mice. The Razer is wired-only, and it has companion software for you to make adjustments to the sensor. On the other hand, the Finalmouse is about 20g lighter, which is impressive as it's a wireless mouse.
The Finalmouse Starlight-12 Phantom Small and the Finalmouse Starlight-12 Poseidon Small are essentially the same mouse in different colorways. The Phantom has a black and gold palette, while the Poseidon has a blue and light-blue palette.
The Finalmouse Starlight-12 Small and the Finalmouse Starlight-12 Poseidon Small are very similar ultra-lightweight gaming mice. However, the Poseidon performs better overall. Its click latency is lower, and it has a better build quality and a straight scroll wheel. Also, it has upgraded Kailh 8.0 switches rather than the Omron switches used in the original Starlight-12. Otherwise, the two mice are extremely similar except for their color schemes.
The GLORIOUS Model D and the Finalmouse Starlight-12 Poseidon Small are both light-weight gaming mice with some key differences. The GLORIOUS is a wired-only model with a slightly larger, right-handed shape. Also, it has companion software, meaning you can customize the settings. On the other hand, the Finalmouse is a symmetrical, wireless gaming mouse with a small shape. It has a significantly better build quality thanks to its magnesium alloy outer shell. Also, its latency is slightly better, and it's 24g lighter than the GLORIOUS.
The Logitech G PRO X SUPERLIGHT and the Finalmouse Starlight-12 Poseidon Small are two ultra-lightweight, wireless gaming mice. The Logitech is better suited for more hand sizes, and it has companion software so you can adjust the sensor settings and remap buttons. Also, its click latency is lower than the Finalmouse, and its feet are rounder, so they provide a better gliding experience. On the other hand, the Finalmouse is 15g lighter than the Logitech, and it has a slightly better build quality thanks to its magnesium alloy outer shell.
The Logitech G Pro Wireless and the Finalmouse Starlight-12 Poseidon Small are two wireless gaming mice with some key differences. The Logitech is suitable for a wider range of hand sizes, and its sensor settings are customizable as it has companion software. On the other hand, the Finalmouse is about half the weight of the Logitech and has a better build quality.
The Finalmouse Starlight Pro - TenZ Medium and the Finalmouse Starlight-12 Poseidon Small are very similar mice in the same lineup but are slightly different sizes with different visual designs. They also have very similar performance, but the Starlight-12 Poseidon Small has somewhat lower click latency. On the other hand, the newer Finalmouse Starlight Pro - TenZ includes very minor manufacturing improvements.
Test Results
The Finalmouse Starlight-12 Poseidon Small has a symmetrical, low-profile shape with two side buttons on the left made of black matte plastic. The honeycomb shell is made of solid magnesium alloy and has an embossed filigree on the left and right-click buttons, the mouse wheel, and the CPI button. It looks nearly identical to the other mice in the Finalmouse Starlight-12 lineup, but it has a blue and light blue color metallic color scheme. If you're interested in another model within this lineup with a different color scheme, check out the Finalmouse Starlight Pro - TenZ Medium.
The Finalmouse Starlight-12 Poseidon Small feels very well-built. The isn't any rattling, loose parts, or wobble present. Similar to the other Starlight mice, the Poseidon has a magnesium outer shell that exhibits no flex whatsoever. The bottom of the mouse is a high-quality plastic called Ultem, which allows the RF signal to escape. Since the bottom is plastic, it does exhibit some flex if you apply pressure, but this doesn't impact regular use. Finalmouse advertises that this model features some upgrades to its quality control. Specifically, on our unit, we found that the scroll wheel is better aligned than the other Finalmouse models we've tested.
Finalmouse advertises the weight of this mouse as 42g, but they also indicate that the weight can vary by around 2 grams due to manufacturing tolerances. The exact weight obtained was 43.74 grams.
The Finalmouse Starlight-12 Poseidon Small has a symmetrical shape, but it's not truly ambidextrous because the side buttons are only on the left. It's a small mouse, so it's well-suited for small and medium-sized hands. If you have larger hands, you'll likely find the Medium version of this mouse more comfortable.
Finalmouse advertises a continuous battery life of around 160 hours, though the actual battery life will depend on how frequently you use the mouse.
The Finalmouse Starlight-12 Poseidon Small comes with an excellent paracord-like cable that's very flexible and doesn't drag on surfaces. It also doesn't retain kinks from the packaging.
The feet on the Finalmouse Starlight-12 Poseidon Small are outstanding. Overall, the Virgin-Grade PTFE and the mouse's light weight create a very smooth gliding experience. However, they make a slight scratching sound directly on a desk, and there are a few sharp edges.
- Finalmouse Starlight-12 Poseidon Small
- Micro-USB to USB-A cable
- Wireless receiver
- User documentation
The left- and right-click buttons on Finalmouse Starlight-12 Poseidon use Kailh 8.0 mechanical switches rather than the Omron mechanical switches used on many of the earlier models of the Finalmouse Starlight-12.
You can use the CPI button below the scroll wheel to cycle between the four preset CPI settings. Also, there's a power switch on the bottom of the mouse. Unfortunately, you can't program any of the buttons as this mouse lacks companion software.
The Finalmouse Starlight-12 Poseidon Small has remarkably low and stable click latency. Playing games in any genre feels extremely responsive.
The only available polling rate on the Finalmouse Starlight-12 Poseidon Small is 1000Hz. It has four CPI presets: 400, 800, 1600, 3200, which you can cycle through using the CPI button behind the scroll wheel.
The scroll wheel on the Finalmouse Starlight-12 Poseidon Small is precise and quiet to use. It has a rubberized finish which adds grip. The scroll wheel on this unit is more centrally-aligned than previous Starlight versions, though some users online have reported that their scroll wheels were off-center or crooked.
There isn't any companion software, so you can't customize any of the sensor settings or button functions.