There's always something wandering around our ranch after dark, and I wanted a light that could really reach out and illuminate those unwanted visitors. Well, this little monster certainly delivers!This ULTRAFIRE 501GX puts out a claimed 600 lumens of green LED light, with a 520–530nm wavelength. I was honestly surprised by how much light comes out of something this compact. The beam is strong, bright, and has some impressive reach. It's exactly the kind of visibility I wanted for checking out those darker areas around the property.I also really like the included accessories. The Picatinny rail mount, pressure switch, and adjustable mounting options make it much easier to get the light positioned where I want it. The hidden USB-C charging port is another nice feature, especially since I prefer rechargeable gear.Where It Lands: Small package, impressive brightness, and plenty of useful mounting accessories. I'm really happy with the beam strength and overall versatility. Those four-legged troublemakers around the ranch won't be quite so hard to spot after dark!

Pros: - 18650 battery measured 2807mAh during a charge / drain cycle (label says 2600mAh) - slim and compact build (keep mounted profile to a minimum?) - beam isn't a great thrower (see photo 1 compared to a thrower with >2000 lumens which was far greater center spot brightness (you can't tell from the photo) but is dispersal is less. See photo 2 -- fairly dark night, trees are 100 feet away and the beam is fairly wide. Not sure about the usefulness at greater than 100 yards. At 600 lumens, what do you expect? - has a fixed brightness level that doesn't ramp down quickly after 1 minute or so as many with far greater lumens do. - it will get hot slowly depending upon ambient temperature obviously. At 78deg F, at roughly 7 minutes, it became almost painful hot -- you'd need gloves or have it mounted to keep it on. - will run 2 hours to become fully discharged and just under 4 hours to fully charged it. Intensity will decrease somewhat as voltage goes down but not dim to nothing. - the 45 deg offset picatinny mount work with alternate switch ok, Personally, I don't like 45 deg offset mounts, but just under 1" diameter, a straight mount is easy to get. - remote switch 3 buttons (raised bump has one to switch it to stay on, and 2 lower ones that do the same thing -- momentary) - USB-C plug is hidden under barrel that is exposed by turning the hood, has o-ring, will connect with USB PD Cons: - not a great thrower or very bright at 600 lumens - USB-C plug is slightly recessed within barrel of light so some USB-C plugs will not connect properly - not much thermal mass and will get unbearably hot after more than a few minutes continuously on (some throwers won't do this, but then they ridiculously large mounted) Not a great thrower due to 600 lumens an average center focus but ok. Will work for a good amount of time on before getting unbearably hot. Nice green flashlight but an average thrower with only 600 lumens.

I received this hunting flashlight securely packaged in a retail hanging box, accompanied by an UltraFire 18650 rechargeable Li-ion battery, a USB charging cable, a rail mount with hex wrench, and an alternate tail cap with a remote pressure switch. All of the parts seem to be sturdy and fairly well made. The flashlight has a single operating mode and is extremely bright, even at range. In testing, I found that the flashlight lasts for about 3 hours of continuous use, on a full charge, and recharging the drained battery likewise took about 3 hours. Overall, a pretty decent and rugged little hunting light, at a more or less reasonable price, considering the included accessories.