RetroNixie is a 4 digit Clock looking like a Nixie tube clock, but is made of acrylic glass. Each digits has 10 acrylic glass slices, engraved with digits 0..9. Each digit has got two WS2812 Led's, an ATMega328P controls the Led's to show the time.
See also on Thingiverse: (http://www.thingiverse.com/thing:1978456)