So i have had this product for a while, and feel confidante in giving it a longer review. I use this for 2 purposes, both on a commuter, and a road bike. The interchange is simple and easy, and it looks good on the bike, but thats not why you buy this. The light is incredible. Often i ride where there are no street lights out in the country, and its dark dark, but the light keeps a beam of joy in front of me. The flash is retina searing if you need a super aggressive daytime light for commuting in heavy traffic. I have never used it like that, but i could see lots of people giving you the bird. Its that bright. For how I use it, I think the dual setup is a little overkill, but might be justified if you ride DH and need a crazy splay of lights. The hi/lo feature is nice for saving battery on long rides. The battery has an led that is blue when your good, and red when you need to be getting home or finding a friend. For a two bill light, i cant see anything being much better. The battery is pretty light, and long lasting both in burn time and in life cycles. Its taken a couple hard drops onto concrete and rocks, and survived with minimal scratches, although Ive never drop it on the lens. Overall Im impressed with its quality and life. when/if this dies i will buy another.