Simple soldering kit by and for the nerds at Spark Makerspace.

Materials:

• 2 x 5mm LEDs¹
• 1 x BAT-HLD-001-THM
• 1 x CR2032 3V Battery Cell

Footnotes

1. Any 5mm LEDs will do, but the ones we prefer can be found searching some combination of these words on your favorite site for sourcing cheap parts: "Slow Flashing LED Diode, Multi-Color Blinking Changing Light Emitting Diodes, 2 Pins Clear" ↩