tecmac 2.4Ghz USB Wireless Optical Pen Mouse Smart Mouse For PC Laptop Computer (Red) Colour:Red   How to use it: 1.Open the battery cover, insert 1 AAA battery with correct polarity (+/-), then open the power switch.  2.Insert the mini receiver into computer USB combo. You can use this pen mouse directly after insert the receiver.  3.It can be used for business meeting, working PPT speech, teaching and other occasions. Product Features: ? Three button + scroll wheel.  ? Battery: 1 x AAA battery (not included).  ? 3 Resolutions adjustable: 800/1200/1600 dpi.  ? Ergonomic design: fits comfortably on your hand.  ? New-modern design and precision tracking optical sensor.  ? Compatible with the equipment: suitable for laptops, tablets.  Product Specifications: * Type: wireless pen mouse.  * Color: red.  * Interface: USB.  * Weight: 17 g * Size: 5.5 x 0.6 x 1 in.  * Operating Distance: 33 feet.  * Tracing Method: optical technology.