This light has three settings, which you access from the button on the end cap. High (220 Lumens), Low (unknown Lumens, but appears to be less than half high) and a blinking SOS signal. The end cap is used to insert the two CR 123A batteries. It has an o-ring seal, leading me to believe it is decently weatherproof, although the packaging didn't mention anything about it.
On high, this thing is bright, blows away the 4 D cell maglite I've been using in the woods for years. Low setting is quite adequate and bright around the campsite. The case appears to be some form of metallic casting, rather than something machined from a solid billet of aluminum, so it may not take quite as much of a beating as other lights.
I don't have an estimate of battery life yet, but it's been fine for a weekend campout.
Pro's - Very bright, small, light weight.
Con's - harder to Rodney King someone with it, battery cost (and possibly life), case likely not as strong as the expensive models.
I'm happy with the purchase.
