Logitech ERGO M575 Wireless Trackball Mouse 

• Minimize movement and maximize comfort with ERGO M575, a wireless trackball with a sculpted ergonomic shape. With no need to move your arm around to move the cursor, your hand and arm stay relaxed.
• The smooth and responsive thumb control can be used anywhere – and since it doesn’t need to be moved, ERGO M575 is perfect for tight desk spaces.
• ERGO M575 has been designed and developed to ergonomically fit the shape of your hand. And with no need to move your arm around to move the cursor you’ll reduce fatigue in your hand and arm.
• With two ways to connect, via Bluetooth® Low Energy or the included USB receiver, Logitech M575 provides a powerful, reliable signal from up to 33-ft (10 m) away.
• ERGO M575 features a super compact footprint since it doesn’t move to control the cursor. It’s ideal for tight workspaces, or for those of us that have desks full of papers, personal items – and sometimes even a bowl of cereal.  
• Make any workspace your comfort zone. This compact setup has the tools you need for all-day comfort and better productivity, from a minimalist keyboard and trackball combo to the right webcam and wireless headset to feel great during calls.