Size: For smaller hands (width up to 7.5 cm, measured flat at the hand's widest point, excluding the thumb) - Ergonomic: - Healthy arm and wrist posture, vertical hold - Unique: Short adjustment period. - Compatibility: Win XP, Vista, Win7/8/10, OS X - A mouse pad is recommended when using a vertical mouse - Adjustable speed (800 - 1600 dpi) 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.