The K350 allows for effortless and secure typing, and the padded palm rest provides a comfortable and natural hand position while typing. The wireless Logitech Unifying receiver is so tiny that it can remain plugged into the notebook, ensuring the keyboard is always ready for use. A compatible mouse or numeric keypad can be easily added with a single receiver. Long battery life: Each set of AA batteries lasts up to three years, and the LED battery indicator keeps you informed at all times. Logitech's advanced 2.4 GHz technology offers maximum freedom of movement with the highest reliability—fast data transmission, virtually no delays or dropouts, and 128-bit AES encryption.