I use an Olight brand M21-X warrior. It's 600 lumens. Momentary or steady. Four settings: low, med, high, and high strobe. Olight is a company that recently teamed up with 4sevens. Fenix is also tied in with 4Sevensix. They all make really good lights. If you look them up, make sure you look for the X part of M21-X. The M21 is 500 lumens. The M21-X is the updated version at 600 lumens. Also if you get a light that takes two CR123s, a lot of them such as the Olight Warriors also take the 18650 rechargeable lithium batteries, which comes in very handy. You usually get the 18650s on line,then just get a cheap battery charger that handles them. 10 or 15 bucks. You can even take apart an old battery pack from a disregarded laptop and it has like six 18650s in there. Most of them are still good even when the laptop said they're not. I love my light! It has good throw (about a 240 meter beam) and a nice blend of flood that really lights up a room. Most that I have showed it to can't believe that a little flashlight (about 5 inches long) put out so much light. (on high)