YBC Wireless Vertical Optical 5 Buttons USB Mouse for PC Laptop Desktop Product summary: CSL TM137U / ergonomic USB mouse / vertical design Particularly arm-friendly for preventing mouse arm/tennis elbow (RSI syndrome) USB 2.0 / optical sensor / sampling rates 1000 - 1600dpi (freely selectable) Precise operation thanks to 1600dpi support 5 buttons & scroll wheel / left & right mouse button / forward & backward button Perfectly suitable for long periods of use on laptop/PC Operates on nearly every surface with a high degree of precision Ergonomic work made easy - Minimise health stresses when working on the computer for a long time! The vertical design of the TM137U enables a neutral hold and provides high comfort. In this way, your arm is held in an unturned, neutral position when working on a PC or laptop and is not forced into a distorted position as it would be when working with a conventional mouse. Simply try give it a go: Place your arms in a relaxed position on the table and note the natural position of your hand - the hand surfaces face each other just as when you shake hands with each someone. This is the same position that this vertical mouse holds your arm in: Just like with handshaking, your arm remains in a relaxed position. Your hand is also supported by the ergonomic design and the anti-slip surface of the mouse. The USB mouse has a right and left mouse button, both a forward / backwards button for comfortable surfing the internet and a dpi selection switch, with which the sampling rates can be switched from 1000-1600 dpi during operation. Due to an optical sensor the vertical USB mouse can be used on almost all surfaces with the highest precision. a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a