ERGONOMIC DESIGN - Handheld trackball helps reduce strain on the palm and wrist muscles during extended mouse use. ATTENTION: If the mouse does not respond after a period of inactivity, click to wake it up. If it still does not work, please check the following: 1. Replace the battery and try again; 2. Turn the mouse off and on; 3. Remove and reinsert the USB receiver. TRACKBALL COMFORT - Ergonomic handheld trackball design helps reduce discomfort associated with prolonged use. Hold the device like a controller and use your thumb to control the cursor. Sculpted shape supports a natural hand position, allowing cursor movement without moving your arm. Suitable for both left and right-handed users. ADJUSTABLE - Wireless handheld trackball features 800/1200/1400/1600 DPI optical tracking for enhanced sensitivity compared to standard optical mice. Equipped with a responsive rolling ball and a stable 2.4GHz wireless connection. Wireless range up to 10 meters (signal may be obstructed by walls). WIDE APPLICATION - Trackball includes a USB 2.0 interface, plug-and-play functionality with no software required. Compatible with laptops and desktops. Not compatible with tablets or smartphones. Compatibility: Windows XP / Vista / Win7 / Win10, Linux, Unix, OS. Powered by AAA battery (not included). Material: Plastic Color: Black Package Contents: 1 x Wireless Trackball Mouse, 1 x USB Receiver Note: Light reflection and display differences may cause slight color variations between the image and the actual item. Measurement may vary by +/- 1-3 cm.