This is a great little light from Exposure. Unfortunately, after many years of use, and some over-tightening, mine broke. I'm a little hesitant to buy another because of the twist on/off, but it's proving difficult to find something of similar micro size that incorporates a CR123 (rechargeable) with a strobe function at around the 100lm level so that the battery last many hours. Just enough light to get you through the first twenty minutes of a predawn mtb race, or convince check point officials to let you pass after the no-lights time cutoff of an ultraendurance because you haven't trained when you have a new kid. ("They didn't say what kind of light. Go!")
Slight increase in lumens since I bought mine. There are a lot of other offerings out there with multiple times the lumens, but this one is really great for its balanced size, output, and life. Also, since the Flash sits flush with the handle bars, there is no knee bumping when out of the saddle.
The Flare is also a really nice taillight, but expect the same issue with the plastic twist head after years. Also, if you have an aero seat post, you may want to wrap a small piece of bike tube to keep it steady.
(both Flare and Flash pictured)