Features:

  • Material: Copper Plastic.
  • Laser Shape: Dot. Outer diameter: 6 mm.
  • Wavelength: 650nm. Working Voltage: 5v.
  • Operating Current: must less than 20 Ma.
  • Can be used to connect diode tubes for multiple use.
Work great, can't beat the price

These are perfect for my project. They work great at as little as 3.0v only consuming 9 mA. They produced a clear laser dot across a brightly lit room when powered at 4v and 19mA.

Lasers you cannot go without

They actually show a dot at 3-20 feet away about 1/16 of an inch. Yes you can adjust this. Excellent soldering on the pig tails. I assume if you bought these you know how to strip very small wires. I bought 20. I just finished Shrink tubing 10 of them, and stripped back a little more wire and tinned them. They all work perfect. I ran 5v. I found you can run them higher but don't know how long they would last. Very happy with these lasers.

Great Little Lasers

Great deal! Cant go wrong at this price. As you can see from the pictures that I posted, Nearly every one of the 40 lasers that I purchased produced a nice and bright red dot. No need to use a resistor if you have a clean and stable source of DC at 5V or less (i got a nice range of visible light from 2.9V - 6.2V). I ran these straight off my DC power supply to a breatboard at 4.8V. I kept about 20 of them at full power for over two hours and they held up just fine. You can also get a pretty tight beam on them if you can manage to break the glue bond in the casing. Actually, I suspect that it isnt glue but rather extra solder that leaked in from when they tinned the leads. About half of mine were loose enough to focus by hand and the other half required a little coaching from a pair of pliers with varying degrees of success.

Great bargain. Exactly what I expected.

Exactly what I expected. I blew up 2 of them testing and found them to perform well with 4 or 5 volts at the leads. Using 4 volts the laser draws about 20 mA and at 5 volts it draws about 30 mA. Over 5 volts, it seems to die rather quickly. Less than 3.5 volts, it gets noticeably dim. Using 4 volts in a well lit room, the spot was very bright at 15 feet away. I didn't see a huge change in brightness between 4 and 5 volts at that distance, so I'm going with a resistor value that delivers 4 volts at the leads to keep heat down and extend life. (1000 ohms with 24 vdc power supply) As others have recommended, heat shrink tubing around the small bit of circuit board sticking out of the back should greatly extend the life of the leads.

Must use right resisor size for EXCELLENT beam...

Hi, how are you? Love those tiny red dots that shoot all the way across the room and freak out your cat? Well, this is the ticket for you, BUT you must use the right current reducing resistor in series with power or you will fry the LED!!!! All you techie wiz-bang gizmo-gadgetiers shut up for a moment, not everyone is as smart as you! :-P All the rest of us need help making things go, okay, listen closely... YOU MUST also purchase a current reducing resistor if you want these to work, I connected these LEDs up to a 4xAA battery pack (6 or so VOLTS DC) and used a potenciometer of 10k ohms and turned it slowly until the LED was at it's peak beam, then I measured the potenciometer and found it at about 220 Ohms, if you use 2xAA batteries, or even 1, you will have to measure for yourself, because the 220 Ohms will probably be too much resistance and your LED will be, like, totally lame. Have fun teasing your cat!

I used this to make a laser parking assist for my garage for under $1

It is very simple, take out the light bulb in your garage motor, add an adapter that lets you plug in a plug and the bulb. This thing can take 5V from any standard USB charger. Plug in a USB charger, take a USB cable, cut the cable, you will find red and black cables. Connect the red to the red you find in this LED, and black to the other wire and stick it in your garage some place where it will shine on your car when you drive in. Voila! I made 3 and saved $75 (Chamberlain's LED parking assist is like $25)

Ordered 20 & received 20 fully functioning 5mW laser diodes

Ordered two of these packages (Total of 20) and all twenty arrived fully functioning. The pre-stripped pigtailing was a nice touch as it allowed me to immediately put them on a 5v power line (!! With a 220 ohm current limiting resistor in series !!) and make sure they all functioned. Sure enough, each one put a nice little red dot on my wall. Pros: Inexpensive Fully functioning Pre-stripped pigtails Laser beams and science and stuff Cons: Delivery time due to sourcing directly from china Unable to blow up the moon My dog now thinks World War 3 through 17 just started at the same time

Very good product, very

Very good product, very, very bright laser. I have bought a Chamberlin “Laser” garage assist. Chamberlin has a small pulsing almost invisible laser dot and if your windshield is tinted then is completely invisible. Replaced with this cheap WYHP laser dot…added a cell phone wall charger 5V and used USB cable from the same charger. Red goes to red and black to black from the laser. WOW!!! The results!!!The laser spot is about size of the penny and 50 times brighter. I did powered permanently from the wall plug of the garage opener, but you can use the same power as the opener bulb, so it will light up only when you open your garage door. Picture compare both dots on the garage floor.

Cats, with laser beams on their heads.

This was an incredible deal. Too good to be true. But yes, 10 working lasers for this price. They work fantastic with my Raspberry Pi. The leads are too thin for a solderless breadboard so be prepared to solder on some thicker wire for playing around with it. They are pre-tinned at least. You can twist it to focus, and it comes present with a glob of hot melt glue but I was able to adjust them with just my fingers. Also ordered from Amazon these photodiodes: 10pcs Silicon PHOTODIODE 390 to 675nm Visible spectral Detector 565nm Photodiodes This photodiode, with a transistor to shift its output to logic level, lets me sense the presence of the laser using Raspberry Pi GPIO. Ordinary indoor light wasn't sensed but I didn't try outdoors. Suddenly we can do some amazing stuff. Also works with 3 tiny button cells. The body of the laser is tiny, which opens up many interesting ideas. I bought 30. Many project ideas like the one in the title. Am very happy.

I'd definately buy again but 10 pieces could last me forever.

Excellent value, shipped free, delivered 13 days after placing order! (fast boat from China to US) All 10 pieces worked out of the envelope. The laser spot is acceptable for the price. (US$0.39 each) They are 'slightly' focusable but @ 6mm there is not much room for optics, better for short (10m and less) than long distances if a small spot is critical. They do leak some light backwards but the spot is very bright. Most 6mm consumer/hobby lasers have similar limitations. They come in a decent sturdy ziplock pouch. Only possible issue I can forsee anyone having with their project is the power supply PCB is wider than 6mm. (you can see that the PCB is slightly wider in the photo) To press into a deep 6mm hole it may need to have a countersink for the PCB. These are great for communication and pointing, I kinda doubt the optics are up to the task of holography (they are powerfull enough). It's a long review for a trivially priced item but they made me smile, and I have many lasers, both gas and diode. Please: Do not ever stare at any laser beam with remaining good eye! ;)

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