This FeatherWing allows you to connect a Particle Electron to the Feather Ethos and utilize any* compatible wings.
The adapter will break out the Lipo and USB from the electron into the feather so has the extra pins that are not normally soldered on the electron, exposed. So when using careful attention of this is required when positioning the electron in the adapter.
A Photon could also be used, but 5 of the Feather Pins will not be connected.
Note: This comes as a kit and the socket and pins are not soldered on the board. A pre-soldered version is available.