Instructables user technoplastique writes:

This bracelet is designed to showcase a special piece of wood veneer. In my case I had a small piece of olive ash that had a really beautiful grain pattern. It was suitable for framing, so I framed it into a bracelet. The LEDs behind the veneer add a warm glow that really shows off the personality of the veneer.

The bracelet has a wood base (plywood, specifically), a veneered outside, a channel for an LED circuit and diffusing resin, and a leather lining/battery cover.

Wood Veneer Bracelet with LED Backlighting