That’s right, they’re back! These fascinator barrettes are staple of technology from Sabins Gadgeteering Lab, now made into a fetching hair or hat clip. The emitter crystal is powered up by a single CR1632 power cell (included), inserted underneath the crystal housing as shown in the second picture. The “bump” (negative) side faces inward towards the crystal housing. There are four different colors to choose from.
These stylish devices cost $20 USD each, plus shipping.