It is a Motoro. This one in particular appears to be a 'chainlink' as the dots around the disk connect all the way around. ECZS has a bunch of small motoros in the 4-5" range for $75, but I opted to spend a little more money and get a well established ray for my first. I'm already learning volumes. You can read and read about rays, but keeping them provides the best knowledge. In the 24+/- hours I've had him, I've spent a solid 3 hours sitting in front of the tank just watching him cruise the tank, up and down the glass, etc.
I've got a question when it comes to feeding though. Is it better to do one large feeding every 1-2 days, or feed small amounts periodically. I'm leaning towards the second option, as it serves as a 'reward' for all of his scavenging. He is constantly on the prowl for food, even if it is a sleeping pbass!