Small, 5mW red laser diode power supply

5pcs per Lot 650nm 6mm 5V 4mW Mini Laser Dot Diode Module Head Red Copper Tube | eBay

Do these small diodes need a constant current driver, or can I just hook them up to a regulated 5VDC power supply?

I think these are ready to go with just a power supply. The driver is built into the module.
These look like the same modules that I used in this mini keychain build.

EDIT: Here's another good thread from Cyparagon showing what you can expect from these, and also an informative thread from hakzaw1. -Here-