450nm Blue Module Diode (Industrial Blue Dot)445nm

Seems to work great. Just a prelim test at 6 volts (minimum seems to be 2.2v to turn on) it burned my black mouse pad. I'm not a pro on this stuff but I've never had a 5mW laser able to burn things 12 inches away, but I'm happy with extra power but just be careful this is way more than a typical 5mW laser pointer, WEAR EYE PROTECTION I pointed it at something dark 30 feet away and had to peak over my glasses and it was pretty frickin' bright.

I purchased both this 450-nm module and the green 520-nm module at the same time, and they share a quirky trait. If I power them from my bench supply by connecting them first and then hitting the power enable switch on the supply, they both produce the faint broadband emission that other reviewers have described. At 3.7 volts they draw only about 4 mA. However, if I enable the power first and then connect the leads, they both lase immediately, drawing about 100 mA. My only explanation is that something in their drive circuitry doesn't like the soft start that the power enable switch on the power supply provides. They require an abrupt application of the voltage to function properly. I confirmed this by simply applying the leads to the terminals of a 3V lithium ion battery. They both lit up immediately. This could explain the inconsistent behavior reported in other reviews.

I set it up on a 6v system for an engineering project. It shines very bright and focuses well.

I had bad luck with blue lasers from this seller. I ordered a blue line laser and a blue dot laser. The line laser is very bright, as it should be. The dot laser in comparison is very dim. I returned the blue dot laser for a replacement, but the replacement was likewise very dim. A properly functioning dot laser should be just as bright as a line laser - the internal components are the same. I would be very pleased to purchase a properly working blue dot laser from this seller, and would order again if I thought this was just an isolated incident. But I've now been through the cycle of receiving a defective product, requesting a replacement, and being provided yet another defective product. I am concerned that they have failed to do adequate quality control on their stock, and I don't want to spend time ordering and returning again and again until I finally receive one that works properly. This is disappointing, and also somewhat confusing, as I have also ordered red and green dot and line lasers from this seller and all of them work properly. I will update if the seller offers me a solution.

Amazing laser, very driver sensitive

I thought it wasn't very bright because it was very unfocused. Once I turned the lens to almost the farthest out position, the spot really narrowed and became a tiny blue sun. Works great on an old 9V battery but the diode housing starts to get warm.

Not to bad, with my cheap variable power supply it seems to pull about .1 amps at 2 volts, which seems to be the minimum operating voltage.

Revised: From 1 star to 4 stars First Review: Just like one of the other reviewers indicated, I too seem to have received a dim LED, not a laser. (Maybe he returned the unit, then it was simply restocked, and the same unit was shipped to me ??) I connected the device to a lab DC supply and carefully turned up the voltage to 7.5V (current of 0.41 amps), but no lasing. Just saw a dim purple/blue output measuring ~100 microwatts. Also, there is absolutely no technical information provided with the unit or on the Amazon website product listing. You would think a short "getting started" description would be provided. Very disappointing as I was hoping to get a 5 mW blue laser. Updated Review: So, I thought I would try one more time. I exchanged the dead laser for a new replacement, which came within 2 days. Now I have a working blue laser! This time I used my lab supply in constant current mode (max voltage set to ~ 6.5 V) and very carefully turned up the current from zero, seeing first light (fluorescence, not lasing) at I = 0.12 amps & V = 1.6 volts, and with more current reached lasing threshold at I = 0.13 amps & V = 5.6 volts. With more current the laser power increased quickly to 4.7 mW at I = 0.25 amps & V = 6.3 volts. To summarize, using a power supply in constant current mode (fine control knob) with a max voltage of ~6.5 V seems to work well. So I basically control the current very carefully (the laser power is very sensitive to small changes in current) and let the voltage settle to whatever value it needs to be to support the current. See the new photos for more detail. It would be nice if some basic instructions were included!