Adesso Wireless Spill Resistant 18-Key Numeric Keypad - Wireless Connectivity - RF - 30 ft - 2.40 GHz - USB Interface - 18 Key - English (US) - Computer - Windows - Membrane Keyswitch - AAA Battery Si - WKB-6010UB

2.4 GHz RF wireless technology - With 2.4 GHz RF wireless technology and 65000 IDs on 12 channels you can enjoy 30 feet of wireless freedom.
Compact & Lightweight - The compact design of less than 3.5" wide makes for easy portability and ease of use in different working environments.
Spill Resistant - The keypad's spill resistant design helps to prevent fluids from staying inside, which would otherwise cause damage to the keyboard.
Quiet Membrane Key Switches - Membrane key switches provide a better responsive and quieter typing experience lasting up to five million keystrokes.
Battery Saving - With the built-in Auto-Sleep feature, you can automatically maximize your battery life when your WKB-6010UB is not in use.
Plug & Play - The WKB-6010UB requires no driver. Simply connect the device to your computer and begin enjoying your new peripheral companion.