To see or be seen ? I have the little usb red lights for the back to be seen. Very light and i don't even know it's on my helmet. For a light to be bright enough to see ( used two 18650 batteries ) and last a while I used a miners head lap. While it was great where ever I pointed my head I had light I found it to heavy and I was always having to adjust my helmet. I took off the heavy head lap and just use the head lights on my bike for being able to see in front.