Sense/Stage XBee 1mW trace Antenna
XBee is a wireless radio board made by the company Digi. These boards are responsible for the wireless communications functionality of a Sense/Stage system. Every sensor node needs one to be part of the network. And at a minimum you will have two of them one on a sensor node, and one on a coordinator node connected to your computer.
This one is an XBee S1 with a chip antenna. It is preconfigured to be used with a Sense/Stage MiniBee. But of course with the software XCTU
from Digi, it can be reconfigured for any other use. The part number is: XB24API001 XBee S1 802.15.4 lowpower module w/ PCB antenna
General overview of the Sense/Stage system: https://docs.sensestage.eu/sensestagev1/overview-of-the-system