Introducing the New Left-Handed Perfit Mouse Optical and Left-Handed Perfit Mouse Classic Plus. Evolving from the original patented shape, the new versions maintain the ergonomic integrity of the time-tested form while adding new productivity enhancing features. The original Perfit Mouse, introduced in 1995, has provided over 100,000 users with unparalleled comfort and performance. Years later, the Perfit Mouse continues to be highly recommended by safety specialists, health professionals and ergonomists. In many instances, the Perfit Mouse is the only solution for eliminating or reducing hand and wrist discomfort while maintaining a high level of productivity. Proactive companies use the Perfit Mouse on mouse intensive workstations because it is highly effective in preventing mouse related injuries. What's the secret? Through years of testing we have discovered a unique posture for the fingers, thumb and palm that is not only great for rapid target acquisition, but also allows maximum muscle and tendon variation throughout point and click operations. Variation is only one of the keys. We also found that when the hand is placed in this balanced posture, local hand muscles come into play. This minimizes the need for flexor muscles that are connected to the fingers through the carpal tunnel. Reduction of carpal tunnel activity is the key to preventing carpal tunnel syndrome. The new optical versions add the latest technology to the unique design of the original Perfit Mouse. A high precision optical sensor provides excellent cursor control. The Perfit Mouse Optical (PMO) places a scroll wheel above the thumb support, rather than on the top of the mouse to reduce the strain on the index finger, which is already heavily used for the primary mouse click. At the bottom of the integrated Thumb Support is the innovative two-position side rocker switch which gives quick and effortless access to two additional programmable buttons. Stop mouse related pain and discover the comfort and performance of the Left-Handed Perfit Mouse Optical and Left-Handed Perfit Mouse Classic Plus. We believe you must feel it to believe it, so we offer an unconditional 30-day money back guarantee. Perfit Optical Mouse has the scroll wheel. Perfit Optical Classic Plus Mouse does NOT have the scroll wheel. Left-Handed Perfit Optical Mouse, Left Hand Regular price: $109.95 Sale price: $99.00 Left-Handed Perfit Optical Mouse Classic Plus Regular price: $109.00 Sale price: $99.00