Feature: Portable finger trackball mouse-with off-table design for free and comfortable operation. It is for ideal for laptop users. It can greatly ease the harm of for palm joint or muscle for long for time using mouse. Avoid sitting closely to the monitor and reduce the harm of radiation and eye fatigue. Dolphin shape design with left/right clickers fit left and right handed users. Plug and for play, no software required. 2.4GHz Wireless connectivity with working distance within 32ft(10m). Wireless Trackball Mouse only, other accessories demo in the picture is not included Specifications: Item Type: Wireless Trackball Mouse Material: Plastic Size: 11x6x5cm/4.3x2.3x1.9in Color: Black Type: With Laser, Without Laser Power: With One AAA battery (not included) Resolution: 1000dpi Wireless Receiving Distance: About 15M/49ft Compatible With: for Windows 98 2000 XP VISTA wins 7 Linux UNIX for Mac OS, ect. Quantity: 1 Pc How to Use: 1.Put your index or middle finger into the hole of this mouse. 2.Control the track ball for moving cursor and press the right and left button with your thumb. 3.When using "Drag and Go" function, press the button in the hole of the mouse that has the same function as the left button of the common mouse. 4.Use the left button to lock the screen and then you can control the track ball to roll your screen freely. Note: Transition: 1cm=10mm=0.39inch Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package Includes: 1 x Wireless Trackball Mouse 1 x USB Receiver