Build Quality

Overall build quality is mostly solid. There is no rattle when shaking the mouse. When applying lateral pressure, minor creaking but no flexing of the shell can be observed. Activating the side buttons by squeezing the sides is possible but requires moderate force. Lastly, accidental clicks when slamming down the mouse do not occur.

Buttons

Main buttons on the Clutch GM51 Lightweight are very good. Pre-travel is low and post-travel moderate to low, resulting in a firm and snappy button response. In terms of feel and feedback, the left and right buttons aren't entirely uniform. While the buttons are visually separated from the shell, lateral button movement is minimal even when provoked. Button stiffness is medium. A pair of Omron D2FC-F-K (60 M) (China) switches are used here.


Side buttons are good to very good. There is some pre and post-travel, but button response is pleasing all the same, and the pressure point is mostly even across the entirety of these. However, due to the height of the mouse, the side buttons sit fairly high and therefore almost out of reach, and their triangular shape makes them stick out, which in turn creates a visible gap between the forward side and left main button in particular. A set of Huano switches (blue plunger) is used.

At the bottom of the mouse is a button for cycling through the set CPI levels, which works just fine. A seemingly unbranded tactile switch is used for this one.

Scroll Wheel

The scroll wheel is good to very good. Noise levels are appreciably low, and tactility is above average, providing decently separated steps and controlled scrolling. The encoder comes from CF (black) and has a height of 12 mm. The middle (scroll wheel) click requires very low force for actuation, which may result in relatively frequent actuation when scrolling. A seemingly unbranded tactile switch is used for this one.

Surface

The Clutch GM51 Lightweight has a smooth matte surface at the top and textured pattern on the sides. Grip is fine, and neither surface attracts fingerprints or dirt too much. They are fairly easy to clean, and there are no signs of wear left after doing so. All in all, very good materials.

Button Sound Test

Disassembly

Disassembling the Clutch GM51 Lightweight is easy. First, all skates except the sensor ring and utmost rear skate need to be removed, along with the screws (Torx T6) beneath them. The rear is additionally secured by two clips, dislodging which is best done by wedging a credit card (or similar) in.

The GM51 shares its tooling with the GM51 Wireless, which limits the efficiency of its design. On the Wireless, the large plastic assembly erected above the sensor would hold the battery, but on this one, it merely acts as something for the FFC (flat flexible cable) carrying the LEDs to attach to. The side buttons sit on their own PCB screwed to the top shell and are connected to the main PCB through a 3-pin connector. The main button switches, scroll wheel, and scroll wheel switch likewise sit on their own PCB, which is positioned above the main PCB at an offset, and slots into the main PCB. Two screws are used to affix the main-button PCB, two screws are used to affix the battery holder, and an additional two are used to affix the moderately thick main PCB to the bottom shell. The MCU is an Nuvoton M484SIDA, whose datasheet can be found here.


As for the soldering and general quality of the PCB, I'm unable to find any noteworthy flaws.