HiLetgo10pcs 5V 650nm 5mW Red Dot Laser Head Red Laser Diode Laser Tube with Leads Head Outer Diameter 6mm

Bought this to make an automatic laser pointer for my cats. My initial fear of the lights being dim were immediately received when I hooked it up to the Arduino. Great performance. Quality so far seems pretty good, however it seems like the wires are lightly soldered on. So far none of them have broken free. Very tiny, which is great, and probably the best value for the money considering quality and quantity. Love them!

Quality laser diodes. Operates directly from 5 volts... coolly,Expected lower quality, due to the low price, butwas impressed with the quality of the product, andwas further impressed that there was more than oneat this price level.

These are Ok red lasers, but not for mission-critical projects. Some just die without warning, and you will need to replace them. I had a project with 32 lasers, two died before I installed them and 3rd one died later. But they are cheap and when they work - they work.

I am using it to align an optical system. It doesn’t need to be perfect so these actually worked out great.They're easy to use, just cool them up and it works. The lens turns to focus the beam.They can be run off 2 AAs, I added a switch in series to make it easier.Its less than the ideal voltage but dimmer is better in my application.I think they're a great value and worth picking up.

All units work. Ran directly off a 4.5V battery pack. Bright, but has marginal particle flare (expected from low cost optics). Beam spread is about 5/8 inches at 25 feet. I've read this can be adjusted, but the brass/copper head is so tight to the body that I fear I'll damage the unit trying to adjust it. Leads are little short - about 3 inches long, but overall I'm pleased with these units.

A good deal but the beam isn't parallel to the housing meaning they're useless to my application

Can’t beat these lasers for the price. I power them with a 3 AA battery box with built in switch. Secure wires with a blob of hot glue for a stress relief. I mounted one in a hole drilled in wood and accidentally pulled the ground wire (blue) loose. No problem, I just stripped the wire and pinched it between the Brass housing and the side of the hole and it still works fine. I wish the body was 1/4” diameter, think it’s metric. Wish I had a few 40 years ago.

This laser diode is perfect for my application which is a laser sight for a Bug-A-Salt unit. However, it pulls 50% more current than the published specifications. The one I tested pulls about 29 mA at 5V instead of 20. I plan to run it from 3 AA batteries in series so I expect it to pull about 25 mA which is fine. The dot size is pretty large but I don't expect miracles for the price, so I'm pretty happy with this product.