This is a cheap and easy to use RF wireless transceiver module based on the popular nRF24L01 from Nordic Semiconductor. It works at the 2.4 GHz frequency range and has a high on air data rate of upto 1 - 2 Mbps and comes with an onboard antenna for best performance maintaining a small size factor. This is one the cheapest and easiest modules to do wireless communications using Arduino, Raspberry Pi and other micro controllers. Libraries and sample codes are available for Arduino and Raspberry Pi which will make it easier for you to start using the wireless module.
Use it to do bidirectional communication between devices. It has a standard SPI interface, which means you can directly interface this module to any microcontroller without the need for any external circuit.
This RF transceiver is perfect to making wireless robots, home automation, wireless transmission of audio and video, etc.