Datasheet

There’s also a 24-pixel RGB ring (http://adafru.it/2268)
specifically designed
for the Particle (formerly Spark)
Photon development board.
This one’s not “see-through” like the others — the space
at the center provides a socket for the Photon
board (http://adafru.it/2721).
© Adafruit Industries https://learn.adafruit.com/adafruit-neopixel-uberguide Page 16 of 68