This is version 2 of the XBee wireless communication module from 63 mW using the ZigBee protocol.
It's the very popular 2.4GHz XBee module from Digi. These modules take the 802.15.4 stack (the basis for Zigbee) and wrap it into a simple to use serial command set. These modules allow a very reliable and simple communication between microcontrollers, computers, systems, really anything with a serial port! Point to point and multi-point networks are supported.
Peak current TX: 205mA
Current RX: 47mA (3.3Vcc)
Quiescent current: <3.5μA
Spacing Range at home (indoors): up to 90m
Spacing Range direct distance (outdoor): up to 3200m
Transmission power: 63mW (18dBm)
Size: 24 x 33 x 9 mm
Strip Connection: 2mm