Ergonomic comfort design, relaxed hand and arm. The comfortable, sculpted ergonomic shape of this mouse naturally fits your hand. Ergonomic “handshake” design greatly reduces arm/wrist/hand strain while providing relief for carpal tunnel syndrome. Back/forward thumb buttons provide extra convenience. Optical tracking technology has higher sensitivity than standard optical mouse, usable Smooth and precise tracking on a variety of surfaces. The ergonomic mouse has 6 convenient buttons design, plug and play. QTY over 1500 ship by sea.