Laser Diode - 5mW 650nm RedAdafruit
You have some frickin' sharks at your lair, and you're thinking "it would be really great if I could attach some lasers to them" and then you see these little laser diode modules: what great timing! These encapsulated laser diodes are Class IIIa 5mW, with a 650nm red wavelength. They can be driven from 2.8V to 5.2V so they're great for your embedded electronics project. You can use these for laser harps, electronic 'trip wires', laser-vision guidance, and more! Simply connect power to the red and black wires and you will be lasing in no time.
Please note: this is not a laser pointer. It's a diode with integrated driver. You still need a 3 to 5VDC power supply. These diodes are 5mW output, and have a safety label marked on them. For more information on laser safety and ratings check out the Wikipedia page