High-speed scroll wheel. Enjoy smarter scrolling, more comfort, and increased productivity. The Signature M650 features SmartWheel scrolling: scroll with utmost precision or high speed, depending on your needs at the moment. Choose the Signature M650 that best suits you. We recommend the M650 for small to medium-sized hands, the M650 L for large hands, and the M650 L left for left-handed users. Working with your Signature M650 will bring you great joy. All mice are designed with a contoured shape, a soft thumb area, and rubberized side grips, ensuring the mouse always feels secure in your hand. Experience more comfort and focus on your tasks.