I love my S1! I have 3 of them and they are great.
I even left one clipped in my pants pocket, washed and dried the pants (in the washer and dryer) with the S1 along for the ride...
It worked and still works perfectly!
Smaller than your thumb, disappears in your pocket. Runs best on a protected RCR123. 4 brightness levels plus strobe. Hard to stop playing with it. Clipped to the bill of a baseball cap it's a perfect headlamp.
