I ran Ed Kearney lights way back early 80's, if anyone remembers those. It was a big ol' round halogen car-like headlight in a rubbery casing, plus a huge lead acid battery that I carried in a rack trunk bag. It weighed about five pounds. Then I moved to a couple of different dual beam halogen systems where the batteries were enclosed in a water bottle. Now I'm running the Fenix BC30R. It's tiny in comparison; it's easily under 1/2 pound. I like that it's one single piece, has two separate LED emitters, four constant levels of 100, 200, 500, and 800 lumens, a burst button for 1600 lumens, and a 200 lumen flashing mode. Plus it has an OLED digital fuel gauge that shows the level setting, and the remaining power in five-minute increments. The BC30R lists for $140, but you can get it for under $100 when it is on sale and combined with online coupons.