The Delux M618 ergonomic vertical mouseis shaped in a way that the position of your arm. What makes this mouse unique compared to the regular mouse is that it keeps the user's hand in an upright neutral posture. It reduces forearm twisting, elbow stiffness and hand weakness so that provides better comfort and relieving wrist pain for long time using. Make your fingers, arm flexible and sensitive is not a difficult problem any more especially with a wrist rest extending pad. DPI Adjustment Adjustable DPI with 3-mode (600/1000/1600 DPI), quickly and easily adjust different DPI corresponding to meet your various need. Removable Palm Rest With a removable palm rest extending from the mouse helps add extra relief, provides better glide and different mouse usage. Accurate and Durable More than 5 million mouse click lifetime, durable and practical. Easy Access Use Side key design with quick thumb function makes it convenient to use for Internet browser forward/backward. Plug and Play Plug and play, no driver needed. Specification: Brand: Delux Model: M618 Color: Black Scroll wheel lifetime: 5,000,000 Operating voltage: 5V Operating current: 50mA Standby current: 16mA Resolution: 600/1000/1600 DPI Shift Power supply: USB System support: for Windows 7/8/Vista/XP Cable length: 160 cm Item weight: 201.2g / 7.09oz Item size: Approx. 13.55 * 10 * 8.7cm / 5.33 * 3.94 * 3.42in (L * W * H) Package weight: 253.7g / 8.95oz Package size: 15 * 10 * 9.5cm / 5.90 * 3.94 * 3.74in (L * W * H) Package list: 1 * Mouse Note: The package list without user manual.