Ergonomics: This mouse fits like a glove Comfort: Reduces muscle tension by relaxing the position of the fingers and wrist. Size: Medium: (170-190 mm between wrist and the top of the ring finger) Practical: 2 ergonomically arranged buttons with scroll wheel Technology: BlueRay sensor for high precision Compatible operating systems: Windows 7 and later, Mac OS 10.5 and later, Linux, Unix BakkerElkhuizen guarantees the longevity of its products. Register your product before the basic warranty expires on the manufacturer's website using the registration code or the EAN number on your product for an extended warranty of up to 5 years on electronics or even longer warranties on non-electronic products! * Extended warranties apply to all non-electronic products with the exception of all gas spring parts, which are covered by a 5-year manufacturer warranty.