Based on the search results, "M2 mouse" can refer to different things depending on the context. Here are some possible meanings:

• In the context of the GK61v2 keyboard, "M1", "M2", and "M3" likely refer to the mouse buttons. Specifically, "M1" is the left click, "M2" is the right click, and "M3" is the wheel click.
• AORUS M2 is a gaming mouse made by Gigabyte. It is fully programmable and saved onboard, and each button can be configured via AORUS Engine to meet your commands. It has a real 6200 DPI optical engine, 50-million-click Omron switch, RGB Fusion 2.0, and an ambidextrous design.
• Keychron M2 is a wireless optical mouse that supports wireless 2.4 GHz and Bluetooth 5.1 wireless connection. It has a strong mouse sensor chip PixArt 3395, with up to 26,000 DPI, up to 650 IPS, and incomparable gripping precision. It also has an ergonomic curved design, stable and ultra-low latency response, and a 1000 Hz polling rate.
• M.O.J.O. M2 is a performance wireless gaming mouse made by Mad Catz. It has ultra-durable 80 million clicks mechanical mouse switches and up to 70 hours of battery life.

Without more context, it is impossible to determine which of these meanings (if any) is the correct one.