The Solas uses a bolt on mount, not the rubber band style mount that was all the rage for the last few years. This is great for those of us who ride on rough roads or singletrack. The light clicks in to the mount very securely and has not had any issues on my dirt road and singletrack rides on my CX bike. It includes a seat post and seat stay mount.
The Solas has 4 modes, the default blinky mode which has a run time of 18 hours, a slightly different blink (which looks like it uses pulse width modulation to fade in and out) runs for 7 hours, Low power on (group ride) 36 hours and full steady of 4:30.
The Solas charges a LiPo (lithium polymer) battery over USB. The charge time is about 1.5 hours for my first 2 charge cycles. The light indicates charge by turning from a red LED to a blue LED.
The rubber part on the bottom there is the charging port.
At 4x times the power of the Planet Bike Superflash and only $15 more you would be foolish to not buy this light. Seriously for $40 this light is incredibly bright and well made. You will save that much on not having to buy batteries for you old blinky with this rechargeable light.
This rear light is great.
Niterider says: http://www.niterider.com/solas-2-watt-rechargeable-tail-light-2013-2/
I just purchased this rear light. I also got a Cygolite Hotshot 2-Watt and tried both of them out. I ended up taking the Cygolite back and keeping this Niterider Solas. It was close but Solas edged out the Hotshot in my opinion.
Recently got the solas, alteady had a smart lunar r1, thought it would be much brighter being 2 watt verses 1 watt. How wrong was i, the smart is actually 10 to 15% brighter running on standard duracells and over half the price. The advantages of usb rechargeable lights is low running costs so i'll stick with solas for now because the runtime is so much better. Still a bit in shock at how bright the smart lunar r1 is though the ongoing cost of replacing batteries every 6 hrs & i do mean 6 hrs, because that's all you'll get on flash mode realistically. P.s. The flash modes on the solas are better.