An extra macro button
An extra macro button on the left, and every button is programmable. A smooth top curve and a thumb rest on the side; 66 ± 3 g with PTFE feet.

An all-round mouse with a PixArt 3950 / 3395 sensor, wired or wireless.
An extra macro button on the left, and every button is programmable. A smooth top curve and a thumb rest on the side; 66 ± 3 g with PTFE feet.
The 8K version uses a PixArt 3950 (up to 30,000 DPI and 750 IPS), and its report-rate button cycles through seven steps from 125 to 8000 Hz; the 1K version uses a PixArt 3395 (up to 26,000 DPI). Motion Sync, and Huano switches rated for 80 million clicks.
Bluetooth, 2.4 GHz and USB-C. The 600 mAh battery lasts up to 140 hours over Bluetooth on the 8K version, or about 70 hours on the 1K version. The Launcher web app remaps buttons, records macros and sets LOD, polling rate and DPI, with 5 onboard profiles.
Summarized from the Keychron website; figures as published by Keychron.
Specs are from the brand's website, which takes precedence if anything differs.