Hi @DeeB Can you clarify some of your questions, as they seem a bit ambiguious. We’d like to get you the help/answers you need.
What are you looking to mount this laser/light on? “picatinny handguard rail” sounds like an AR rifle. Is that what you meant? Many pistols have a picatinny rail underneath the barrel, but it doesn’t have a handguard so that’s a little unclear.
I’m not aware of a weapon light that has an SOS function, but most of them do have a strobe function. Is that what you meant? Some folks really like a strobe as it is disorienting to whoever is looking at it. However, I find the strobe also disorienting being behind the firearm, so I don’t use it. A good weapon light with sufficient lumens (usually over 500lumens, depends on the distance) will absolutely disorient/distract (and possibly even pain) someone if you aim it at their eyes/face.
- which brands are reliable
For pistol lights, the major players are Surefire (USA made, expensive), Streamlight (I think USA/China made depending on model, very reasonably priced), and Olight (relatively new player, China made, very very reasonably priced). There are lots of other choices as well, but IMO these are kind of the flag-bearers in the light market for pistols. Rifle lights are a bit of a different animal.
If money is no object, grab a Surefire. They are absolutely positively battle-tested (literally) and are widely used among LEO/MIL for duty use and will withstand tons of abuse and/or last virtually forever. They have an outstanding reputation. If you plan on carrying this pistol/light combination, holster support should be very good. I do not think any of these models are light/laser combos, they are light only. These mostly use disposable batteries.
If money is an object (as it is for most of us), Streamlight has several models that have very good light output, are very widely used (good holster support if that matters), have several different sizes, and have a very good reputation. Several of their models have light/laser combos. These mostly use disposable batteries.
Olight is the newest player and is perhaps the most innovative. Their lights have outstanding output and have choices with either disposable batteries or rechargeable (or both!). Their recharging options are super hi-tech and neat and convenient. They have a variety of sizes/form factors, several of their models have light/laser combos. They do not have the long-term reputation that Surefire and Streamlight have, but most people like/love theirs. Because they are newer, they do not have widespread holster support if this is for a conceal carry pistol.
- what makes the product reliable
Mostly, it is experience and reputation of doing things the “right way” for a long time. But basically the materials used, assembly methods, electronics components used. Buy from a reputable brand with good customer service (like the ones listed above) and you should be fine.
- pros/cons on certain products/features
- any “must know” info when it comes to flashlights/lasers
This kinda depends on the features you want. Everything is about finding the balance of light output (lumens), light distance (candela), run time, size/form factor/weight, and cost.
The green lasers have also caught my attention
Red vs Green laser. Green is generally considered by most people to be more viewable in more situations than a Red laser. Green lasers used to drain batteries faster, but newer models that seems to not be an issue. Green is usually a little more expensive. Mostly this comes down to personal preference as you individually may see red or green better. Some lights have an integrated laser (especially pistol lights), but rifle lasers will usually be a separate component.
Thank you for your time.
If you have a budget or price range, and can tell us exactly what you are mounting it on and what the use-case is (home defense, concealed carry) we can probably give you a narrow range of choices to look at.