Here's a video of it from youtube
http://www.youtube.com/watch?v=SpmMYIDCrZw
It shows the designer, Sharon Schamber using it. I did buy it, and although I am still a beginner with FMQ, find this makes it easier. You do need to have the Supreme Slider or the like to work with it.
I've also got gloves, and if I am sewing in the ditch, or grids, will use them instead. For FMQ, thus far I prefer the Halo & Slider combination.