Logitech Ergo M575S Trackball Wireless Mouse Work in your comfort zone Minimize movement and maximize your comfort with ERGO M575S wireless trackball - now with quiet clicks. With thumb control you won’t need to move your arm to move the cursor, so your hand stays fully supported on the sculpted ergonomic design. A good and snug fit for most hand sizes. Less movement. More comfort. Keep your hand and forearm relaxed with thumb control for all-day comfort. The sculpted ergonomic design of ERGO M575S puts your forearm in a more natural posture, and reduces the muscle strain in your forearm by 25%. Save space with thumb control As you won’t need to move your hand to move the cursor, this wireless trackball is ideal for small or busy setups - plus, it works on any surface. Certified by ergonomists ERGO M575S was developed with Logi Ergo Lab experts and is user-tested and certified by ergonomists to reduce muscle strain and work in a more natural posture.