The IntelliMouse Web PS/2 combines the scroll wheel with an award-winning ergonomic design. By streamlining navigational tasks, such as scrolling in Web pages and documents, IntelliMouse Web sets an advanced standard for pointing devices. Use the wheel to see either close-up or big-picture views without having to use menus or toolbars (in compatible applications). Also, you can use two additional buttons on the side act as forward and back buttons for your browser or you can program them. IntelliMouse Web is designed to be comfortable. Its raised back fits the palm of your hand, and its side is curved so it's easy to hold - whether you're right-handed or left-handed. Features Two Additional Buttons for Easy Navigation: Get faster, more accurate Internet navigation without using toolbars or the keyboard. The two buttons on the side act as forward and back buttons for your browser or you can program them. Wheel for Scrolling and Zooming: Save time and steps. Move through documents by simply rolling the wheel forward or backward-instead of clicking on a scroll bar. Use the wheel to see either close-up or big-picture views without having to use menus or toolbars (in compatible applications). Wheel for Hands-free Scrolling: Work hands-free with AutoScroll Press the wheel, set the scroll speed, then watch your document scroll automatically. Arched Shape for Superior Comfort: The comfortable, arched shape holds your hand in a supportive, natural resting posture, and the rubberized sides are flared for a better grip and feel. With IntelliMouse Web, superior comfort is in the palm of your hand. System Requirements: IntelliPoint version 3.0 software (included); Microsoft Windows. 95, Windows 98, Windows NT. operating systems; Workstation 4.0 Service Pack 3 or later, or Windows NT Workstation version 4.0 operating systems; 30MB of available hard disk space; Round mouse port (PS/2-compatible) or 9-pin serial port; CD-ROM.