Mouse Included: No Normal Keys: 104 Operating System Supported: Microsoft Windows 7, Windows Vista, and Windows XP (excluding Windows XP 64-bit) System Requirement: 1 USB Port Dimensions: 18.5" x 6.89" x 1.29" Features: Contour: It’s familiar, yet modern All the keys are the same size and in a familiar place, even with the Comfort Curve. The slim, glossy design saves space and makes a statement on your desktop. Ergonomist-approved Comfort Curve design The Microsoft Comfort Curve encourages natural wrist posture, plus it is easy to use. Easy-Access Media Keys Control your music and videos, and open the Calculator with the touch of a key.