Review on M Wave Safety Flag Neon Yellow by Mike Phillips

Not clear from the description, but the light at the end of the flagstick flashes when the flag moves. Because it's mounted on a spring, the flag will flash when you pass a bump. I also found that in low light I could reach back and shake the flag a little to warn a car approaching from behind. I don't recommend making this your only source of light! Most states require a permanent or flashing tail light (and a white light up front) at night. I think it's a great idea to have a flag on a pole pointing in the direction of travel and would love to see this become the standard for commuting cyclists.