I already own the Lunar R1 - 1watt light, which sits on my seat post. The R1 is an extremely bright light and an excellent product (5 stars!)
I wanted another light, that I could attach to my hydration back pack, so was thinking of buying another Lunar R1 light - until I saw this double light. I had a concern, that the lights were 1/2 watt each and may not match the brightness of my Lunar R1 - Well, I am glad to say, that this light is as bright and to be honest, i think this light is superior to the Lunar R1.
I now ride with the Lunar R1 1 Watt on the seat post and the Lunar 2 x 1/2 watt on my back pack. There is no way a driver will fail to notice me in town or in the country. (I am a driver !)
I also own a magicshine MJ-816 1400 Lumen front light (another great product!), so I only like the bright lights !!!!
Various different light modes, which would please most people.
Would certainly recommend !