"Feature: * 100% brand new and genuine made in Korea. * Ergonomically designed to reduce strain * Prevention of mouse hand * User convenience with wow-pen's signature, pen-grip comfort. * Five button, full function mouse * You pick the hand position that best suits you. Plug and play, compatible with Mac and PC. * Specifications : -- Interface: USB (Cable 1.5m/5ft) -- Resolution: 800dpi -- Button: 4 buttons in default / 1 scroll wheel (middle button) -- Operation System required : Windows 98/Me/2000/XP/Vista/Win 7 -- Dimension: 102(W) X 85(D) X 72mm(H) -- Weight: 200g (include USB cable) -- Colour: silver as piture The Symptoms of ""mouse hand "" ： Since the keyboard and mouse have a certain height, the wrist have to dorsiflexion to be an angle , then the wrist will keep the tension for a long time which will compress the nerves blood vessels in Carpal tunnel , so that nerve conduction is blocked at the same time blocked the blood supply, resulting in the barrier between your palm feeling with movement .Mainly for the gradual emergence of hand numbness, burning, night intensified the pain , often woke up in dream. Maybe the ' mouse hand ' occurred while happening the following symptoms : * the palms, fingers, wrist, forearm and elbow stiffness, pain, discomfort. * hand tingling, numbness, coldness. * lower Interoperative capacity of grip strength and the other parts of hand. * night pain. * the pain can be persistent to the arm, upper back, shoulder and neck. Package include : *1 x VERTICAL MOUSE with original package"