ID for Off-Brand 1x1 Round Plate, Stud on BOTH Sides (1 is Hollow) I have a round 1x1 plate (from a blind by-the-pound secondhand sale) with a male stud on both sides of the plate, no female holes. One stud is hollow, the other is solid with a large "C" and a smaller "3" next to it, similar to a cubed notation (superscript). I think it might be C3, (Create, Construct, Customize), but I don't know how to find individual parts for that brand.

So what is it from, and how can I get more? These things are amazing for inverting directions!
I don't know this exact brand, but please note that Mega Bloks (now Mega Construx) has those male/male studs. They appear in many of their sets and come in many different colors. They are exactly one plate tall, just like the one you have on your picture. The Mega version has a hole going through the middle to accommodate any bar shaped piece, which makes them even more useful!