All products reach: FCC, CE& UL standard 19keys & convenience Every language is available 2.4G wireless numeric keyboard, effective distance: 8-10m Keystroke lifetime: Over 10000000 times System requirement: Windows 98/2000/NT/ME/XP/VISTA Working temperature: -20-45?C Working humidity: 10%-90% Keystroke pulling power: over 1kg Key switch elasticity: 55+/-7g Every keyboard in any color is viable