Features: Advanced 2.4 GHz wireless that reduces interference in busy office environments 128-bit AES encryption for a secure connection between keyboard and computer Battery life up to 3 years and low-battery indicator to help eliminate surprises Fast, easy setup - pre-paired wireless connection and no software to install Time-saving hot keys and extra number-pad keys for added convenience Package Contents: LOGITECH Pro 2000 Cordless Keyboard USB mini-receiver 2 AA alkaline batteries (pre-installed)