3V to 5V can be directly applied, for 12V use a 100 ohm resistor
Technical Parameters
Model: LD-G650A03
Output: Red dot (650nm)
Size: Φ12.0x35mm
Cable length: about 135mm
Net weight: 13.5g
Voltage: 3.0V-5V
Current: 40mA()
These little laser diode modules consist of a red laser diode and collimating lens, all in a compact plastic package.
They have a resistor onboard, so just feed them 5 volts and you're done. If you want to use a supply over 5 volts, you need to limit current to these, just like a LED.
These are nice bright laser diodes and they are ideal where you need a low cost unit for general experimentation.
Note: being a laser diode module, not a complete laser pointer, there are no power restrictions on these devices. However, we encourage responsible use of lasers. Never look directly into the beam, or direct the beam towards other people or animals. Never direct the beam towards vehicles or aircraft.
Specs:
Output Power: 2-5mW
Wavelength: 650nm
Working Voltage: 3V to 5V
Laser Shape: Dot
Working temperature: -10° to +40°
Lens: Plastic
Housing: Plastic
Dimensions: 11.8mm diameter x 23mm long
Lead Length: 70mm