product description:
*Patented design, innovative input device, off-desk and no operating space restrictions
*Simple control with thumb, 4D scroll function, to avoid wrist and muscle damage
*Compatible with WINDOWS95/98/2000/ME/XP and WINDOWS NT
*PS/2 and USB interface
*Resolution 200dpi
*Cable length: 2M
*Optional colors: black, white
Instructions:
1. Put your index finger or middle finger into the ring, use your thumb to control the trackball to move your cursor and operate the front left and right buttons. If you use the drag function, you can use the buttons in the ring. This button has the same function as the left button. In the same way, you can control the dragging direction by holding down the button and thumb to perform the dragging function.
2. With 4D function, just press the left button to lock the screen and use the trackball to control the screen to scroll up, down, left, and right, eliminating the need for a mouse to scroll the screen.
a. Hold in the hand for use, no flat support is required
b. Sit on the sofa or lie on the bed, easy to use
c. Greatly relieve wrist soreness and cervical discomfort
d. Suitable for a variety of casual games, convenient and comfortable