The RF401A is a 900 MHz radio designed for license-free use in several countries, including the United States and Canada. It provides a hassle-free way to create long-distance wireless links between your computer, data loggers, and measurement devices. The RF401A has a 910 to 918 MHz operating-frequency range and a configurable transmit-power output of 5 to 250 mW. Campbell Scientific recommends the RF401A radios for existing installations that require compatibility with products such as the RF401, CR206X, CR211X, AVW206, and AVW211. For new installations, Campbell Scientific recommends using the RF407 or RF451. Note: The image depicts the RF401A with an attached antenna. The antenna is sold separately.