Kensington Pro Fit Ergo TB450 Bluetooth 2.4GHz with Dual Wireless Capability, Up to 18 months of Battery Life, Ergonomic 34mm Thumb Operated Trackball Mouse, Made from 50% Recycled plastic (K72194WW)50% of overall plastic is recycled material Kensington is committed to help reduce the impact of plastic on the global environment Sculpted ergonomic design provides all day comfort, featuring a unique 45 tilt that helps improve wrist and forearm alignment, the TB450 offers 4 switchable cursor speeds (400, 800, 1200 and 1600DPI) Choice of Bluetooth Low Energy (LE) and 2. 4GHz wireless connection options, 2. 4GHz nano receiver included A patented ball