I have Surefire and Stream lights they are both awesome. My company purchases these http://www.inovaligh...features_t4.php I used one of these in the Baltic sea at -20 Celsius temperature offshore for 12 hours straight It was dropped onto the deck approximately 30 feet and still worked. I was impressed with that but what really impressed me was that while working on our submarine in Brazil, one was left in the frame of the ROV. We had the Sub in 1700 Feet of seawater for over 100 hours. While doing maintenance on the ROV I found it. I took it apart and sprayed contact cleaner in it waited 20 minutes and tried it, it worked! these are the best flashlights I have ever used at 227 Lumens they are extremely well built and bright and worth every red cent spent for one!