I like to have a tat about, even better when the tat is free or redundant stuff.
I've made this gizmo with a very definite use, from 'free' parts.
The LED cluster came from a recycled low voltage lamp. It had a blown rectifier and all the surface mount resistors had increased in value by a large amount, so some fettling was in order. The black case was left over from a switch mode PSU when I used the innards in something else and the battery pack and associated contact strip was redundant from a hand held airband radio that was converted to a base station.
Can you think what it's used for?
Alan