Performed a mini "stress test" with this light. I love it. Let's hit the high points real quick.

Pros:
1) This is an insane bargain. Comes with everything you need (if you have a picatinny rail system) to mount. (Basically, read the product description... that speaks for itself)
2) This thing is BRIGHT. 1000 lumens... I went outside on a full moon and was able to see out to approximately 150 meters with no problem.
3) I'm sure they have to put "water resistant" and not "waterproof" for a liability perspective, but, that being said- I submerged it in water for 5 minutes, took it out, clicked it on and voila, it worked with no problems. Do I recommend doing that? No. But a rainy day or some water splashing on this thing should he absolutely no problem.
4) The price point for a quality light like this speaks volumes alone.
5) This will run (depending on if you have cheap 18650 batteries or not) for a couple of hours. Not bad for a cheap light at all.
6) I threw it up in the air, twice, to about 25 feet at the apex onto regular ground (not concrete), and it functioned just fine.
7) Having it mounted vertically, I have a clear sight picture with my irons that eliminates the need/want for night sights- but that comes down to personal preference.

Cons:
1) I have nothing to secure the on/off switch to my rail- BUT they never advertised having some velcro or anything as part of the package anyway... so this isn't really a con whatsoever, more of an observation.
2) I should've bought this light sooner.

So there you have it. On the cheap, you can have a solid light for your truck, gun- whatever you need it for.

Update. After emailing and complaining to Okeba ..they apologized and were going to send me a teaching number the next day for a replacement part. 2 days later still no teaching number. The flashlight is bright for me but not getting what I paid for "a working pressure switch" pisses me off.. Especially when they company can't even do what they way. The company sucks and the switch sucks but the flashlight itself I like.

So far I didn't even turn it on and the pressure switch wires fell right out. I didn't even mount the pressure switch yet and was not pulling on it hard either. Construction of the flashlight feels good and seems solid. Offset mount is nice too.. Contacted the seller immediately but based on other reviews I don't expect to get a response back. So far nothing in my email not even a notification that they received my email. I didn't even buy a battery yet.

One word " WOW "....It was time to replace the tactical flashlight on my Mossberg 500 12GA. The one I replaced had to be on her for at least, and I'm just guessing, at least 8 + years. Yea I know, too long, but it worked & she was pretty bright. A few weeks ago I noticed that the beam was kinda yellow, yea, DER, time to replace the battery. So I popped in a brand new lithium as usual, as I've done numerous times over the years, but the beam was still pale yellow.....HMmmmm, I said to myself, " thats odd, I know the battery was brand new ". I then tried another one which was brand new, and yet still, the beam was a pale yellow..... " Hhhmmmm, I thought to myself again "....The plot thickened....I cleaned the lens, inside & out, & checked to make sure the contacts & terminals were nice and clean. I figured it was just time to replace the little guy. And being a hardcore & loyal Amazonian I looked at about 9,567 different tactical lights...lol..and I also ALWAYS READ & POST REVIEWS BEFORE I BUY ANYTHING. So, flash forward I decided on this light kit, which comes with pressure switch. Amazing, how bright it is. It blows away the other one I had on it before. Obviously, with advances in LED's & Lumens, my old one was just not up to par anymore. So, there ya have it kiddies. I hope this helps my fellow Amazonians who want to upgrade/replace there old tactical lights....I haven't had a chance yet to take it to the range & test it....I will update my review when I get a chance to shoot it and let ya know if it help up, or it flew off and hits the guy next to me at the range....
.....And YES, in case your wondering, I do have too much time on my hands to write a review such as this. Always remember & never ever forget that it ALWAYS better to write long reviews & just browse Amazon WHILE AT WORK..!!...LOL...ALWAYS, ALWAYS do this on COMPANY TIME...!!
Good night & Godspeed.....!!...Oh, and may the force be with you, always...

The mount is fantastic, i have it mounted on the top rail of my KJW KC-02 with a reticle scope. The angle it sets the flashlight at, you can't even see a hint of the flashlight. The actual flashlight, however, is complete garbage. Unless mine didn't go through any sort of quality control. Doesn't matter what mAh I use of a 3.7v 18650 battery... sometimes the light will come on, come on and flicker then go out, or if it doesn't turn on at all... I'll come back to it in a few minutes and the light is on. I replaced the flashlight with a superior flashlight, a Streamlight rechargeable tactical flashlight. And with the on/off button at the back of the flashlight, its right where my thumb rests and is quick to access. And just to add to the disappointment of the flashlight... THERE IS ABSOLUTELY NO WAY THIS LIGHT IS 1000 Lumens, I think an extra 0 was added. It's 100 Lumens, at best. UPDATE: I contacted the seller about the issue and they responded immediately and are shipping me a new light and not worrying about the defective one. That's great customer service right there.

So far this has been a great flashlight it's very bright plenty of light to light up any hallway or room or temporarily blind someone and the construction seems durable enough to take some light abuse. Haven't shot the shotgun with the light attached yet but will update how it holds up when I do. I love that it uses the 18650 batteries they are cheap, powerful and last a long time. The one negative thing I can think of is the on/off switch attached to the wire is a little bigger/thicker than expected and doesn't come with anything to help attach it to the gun so I decided it's much cleaner without it overall I'm very happy with the purchase.

Update! 1/12/17
I decided to give this flashlight a durability test by shooting by 12 gauge without taking it off. I shot about 60 rounds of 2-3/4 target, 25 rounds of 2-3/4" buckshot, 5 2-3/4" slugs and 5 3" magnum slugs (freaking awesome). When i got home i noticed my light wont turn on it had a new battery I used a couple time for like 3 seconds so that was disappointing until I realized this battery was damaged from the recoil and wasnt letting any power out. After i replaced the battery the flashlight worked perfectly again I'm very impressed a cheap light held up even when my pica-tinny rail was getting dented and the battery broke this is one awesome light!