Docked together, it works as a contoured ergonomic mouse with full palm support and a combined weight of 85 g (3 oz). DS21：Modular Ergonomic Mouse & Handheld Air MouseThe interesting part isn’t just another unusual mouse shape; we’ve seen plenty of those before. When you detach it from its base, the DS21 core becomes a compact air mouse and presentation remote. Use the ergo mouse to set up a presentation on a laptop, and the handheld air mouse module to control the show MBox/KickstarterThat freedom makes it useful for more than just conference-room presentations. Fully assembled on a desk mat, the modular unit provides the contoured palm support of a traditional ergonomic mouse MBox/KickstarterBack at the desk, the core snaps magnetically into the shell to function like a traditional, palm-filling ergonomic mouse.