Ergonomics - using computer For long hours on a daily basis is the New normal for people both work and leisure However what comes after is major wrist pains resulting from all movement back and forth across a desktop by using mouse Perimice-517’s ergonomic design offers a natural-shape platform for your hand to rest on comfortably Equipping with 34mm trackball and 7 buttons full control of everything is now within your fingers Set your wrist and palm muscle free Just enjoy the effortless computer use from now Specification dimension 130x107x45 mm Weight 120 g sensor laser trackball size 34 mm dpi 1000/1600/2000 silent click yes cable length 1 8 m buttons 7 system requirement Windows system and USB port