This project is my second design with snowy owl. It is a bit bigger than Purple Snowy. It has a CR2032 battery and a butterfly clutch on the back. You can wear it and it blinks its eyes. Get it here at Tindie, www.tindie.com/products/nwmaker/snowyowl2/ It comes with two different colors, white or purple soldermask. It uses a dual inverter NL27WZ04 to drive the blinking of LEDs. This chip is not often used or mentioned for ring oscillator.