I just got a pair of the $19/each Blitzu lights from Amazon and rode with them this morning. Red on the back, white up front.
They're pretty good. For the price, they're outstanding.
I would prefer my lights to have combination steady with flash over it, but that's easily solved by running TWO lights. Only more expensive lights do that.
I think it's a good recommendation as a first light. Seems like the mount is very good, it's bright and visibility is 180 degrees. USB rechargable, and finally someone has moved on to micro USB. Also the wider/larger light surface is more noticeable than a point source.
Right now the only light that I have that I think beats it is the Designshine, which costs 10x more. My other taillights now are a Performance Axiom Pulse 60, a Cygolite Hotshot, a Knog Blinder 4V and the lights on the Fly6.
The white front is good as a be seen over the top of my normal headlight, but the wide dispersal means that it's in my field of view no matter how I point it. In full dark (this morning also in heavy fog) it's incredibly irritating after a few minutes of it. I'm going to have to add some tape, or a 3D printed shield, or try to figure out somewhere to strap it where the bike will block it from my line of sight.
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Work: the 8 hours that separates bike rides.