I picked up a new tail light yesterday. It's a combination LED and laser lights. The lasers create two red lines that outline a zone around the back of the bike and creates an area that hopefully, drivers will avoid. I liked the idea when I first heard of it and the price seemed fair on eBay. It was just over $10.
The actual tail light portion has 5 LEDs and 3 modes. Solid on, all flashing, and single LED rotation. The last mode cycles through all 5 LEDs one at a time. It's not the brightest tail light, but I bought it mainly for the lasers!
The two downward firing lasers have two modes. Solid on and flashing.
Here's the video.
I mounted it to the back of the Topeak MTX Explorer rack with the help of a small section of PVC tubing. The Topeak has an inverted "T" shaped plate which isn't very useful for mounting 3rd party lights, but a quick use of a pair of plyers allowed me to break off the wings of the "T" and use the remaining stub to mount the PVC tube.
Rear bottom view showing the laser ports
Bottom of the LED/Laser light