BIGtrack 2.0 is a USB mouse that includes a large 3-in / 7.62-cm trackball. The sturdy base of BIGtrack 2.0 allows the user to easily move and position the mouse cursor on the computer screen while using fine or gross motor movements of the hand, arm, or foot. Once the mouse cursor is positioned, two over-sized buttons are available for left and right clicking.. BIGtrack 2.0 Includes: Large 3-in / 7.62-cm trackball Updated design Two switch jacks for left and right click Color differentiated right and left click buttons USB connection (USB Type A receptacle required) Drag Lock The drag lock feature enables a user to move objects on the screen without having to hold the mouse click button down. To activate the drag lock feature, position the mouse cursor over the item you would like to move. Once the cursor is positioned, double right click to lock onto the item. Once locked, the user can move the item with the trackball. Once a desired location is reached, activate either the right or left click button one time to release the object. Switch Access BIGtrack 2.0 includes two 1/8-in / 3.5-mm mono (TS) switch jacks. Plugging in a switch on the left side of BIGtrack 2.0 will enable the left click via the switch. Plugging in a switch on the right side of BIGtrack 2.0 will enable the right click via the switch. Switch are not included and sold separate. Compatibility BIGtrack 2.0 is compatible with most laptop, desktop, and tablet computers that can use a standard mouse. One USB Type A receptacle is required. To Scroll, place cursor on scroll Bar and press button to scroll.