
Adafruit UV/UVA 400nm Purple LED 5mm Clear Lens, 10 pack
Need some really bright LEDs? These emit UV 'blacklight' in the UVA spectrum so they are great for projects with fluorescent materials referred to as UV/blacklight-reactive or 'glow-in-the dark'.

Wires, Buttons and LEDs! by Lee Cyborg
All About Wires, An Instructive Appreciation of Buttons and Switches and Love LEDs. Learn all the things!