Full-size optical mouse comfort-fit for your hand size. Scroll smarter: With Logitech Signature M550 Wireless Mouse you get line-by-line precision for documents and super-fast scrolling for long web pages; simply switch modes with a flick of the SmartWheel. Upgrade your comfort: This work mouse provides long hours of comfort thanks to a contoured shape, soft thumb area, and rubber side grips that keep your hand snug and in place.