The second Adafruit came out with 50mm LED rings, I knew what they were for. Made in 2013, these were built following the excellent tutorial over on the fruit, only I used a Tiny Lily instead, and attached the LiPo battery to the exterior because I’m not strapping a small bomb that close to my face. I wore these at Makerfaire NY the first time out, and ran in to Becky Stern wearing earrings with the same Neopixel rings. It was pretty neat. Eventually I got around to customizing the Confetti code from the FastLED library. It’s a good balance of showiness and efficiency, and they run almost a full event day on one 250mAh battery.