30 days money-back and 12-months guaranty, when you are not satisfied with our product or you have any question, please contact with us to get a after-sale service, we will give you a satisfied response within 12 hours. This Left-Hand Ergonomic Vertical Mouse is designed specifically for left-handed users, encourages healthy neutral "handshake" wrist and arm positions for smoother movement and less overall strain,care more about your health,once you get accustomed to it,you will love it! Adopted advanced 2.4GHz wireless technology, work stably and fast within 33ft/10m distance with no interference Easy to use:just plug the USB Nano receiver into your computer's USB port with no extra driver needed Switch the DPI levels between 800/1200/1600 to adjust mouse responsiveness Ergonomic Design: allows the wrist to naturally stretch, you will remain comfortable even after long hours of clicking, tracking, and scrolling Specifications: Type : Wireless Vertical Left Hand Mouse Dimension: 4.92*2.56*3.23 inch Material: ABS Color : Black Net Weight: 3.84 oz Resolution: 800/1200/1600 DPI Button: Left/Right Button,Forward/Backwards Button,Roller Button,DPI Button Package included: 1x Wireless Vertical Mouse 1x USB Receiver Please Note: 1. The Batteries are not included. 2. The Mini Receiver is stored into the USB receiver slot in the bottom of the mouse,near the battery slot 3. The previous/next page thumb buttons are not recognized on the Mac OS X 4.This ergonomic mouse size is Great for Large hands/Men's hands, may be NOT very comfortable to Women or Small Hands. It may take several days to get used to. If it does not fit your hand well, contact us for refund without any hassle at any timeWIDE COMPATIBILITY: Support Windows 2000/ ME/ XP/ 7/ 8/ 10/ Vista/98, Mac OS,Linux and more.Fit for Notebook, PC, Laptop, Computer, Macbook and other device. ?PERFECT GIFT?Perfect christmas gift for men women mom dad daughter wife boyfriend grandparents grandma grandpa teenage boy girl sister teacher brother coworker neighbor husband. EASE USE: Six buttons give you improved control over your computer's systems. Whether dragging and dropping, selecting large volumes of data, or casually gaming, this mouse provides a low-cost, effective solution for multiple computing needs. ADJUSTABLE SENSITIVITY: 800 / 1200 / 1600 DPI Resolution Optical Tracking Technology provides more sensitivity than standard optical mice for smooth and precise tracking on a wide range of surfaces. THUMB BUTTON: Forward/backward buttons for ease webpage browsing, the superior choice for internet surfers, gamers and people who work at length at the computer. ERGONOMIC DESIGN: Specifically designed for left-handers, fitting the contour of your palm for maximum comfort.