Assistive Technology Loan Library item === Large trackball with buttons for mouse actions. Also includes a switch interface jack for assignment of buttons to a switch. This allows the ball to be moved as a mouse and a separate switch (e.g. head switch) to be used as a mouse click or double-click. 3 inch trackball . The large ball requires less fine motor control than a standard trackball (from website). It has a left and a right mouse click button located behind the trackball to avoid unwanted mouse clicks. The BIGtrack also allows for 2nd Mouse Connection both the BIGtrack and a second mouse can be connected allowing simultaneous participation. The bright large 3" trackball helps to make mouse movements easy and accurate. Website: www.infogrip.com.