YMMV, but the door doesn't line up properly with the base on the unit I received. The hinge was very rough and didn't open properly until I flexed it numerous times, which rubbed a spot off the back that now looks like a dry, scuffed elbow. The door closes VERY securely thanks to the magnets, but there's no spring, so you have to push it open and hope friction holds it up. And it only opens about 80 degrees, so it's hard to load with a paintball pod.
The door hinge and **** mount protrude below the ring, the ring is very shallow, and it's slightly larger than standard "paint ball hopper" size, so it doesn't fit on my 3D printed hopper. I don't know why they'd sell it separately if it's not a standard size and they don't include the size in the description.
I've been more than happy with every other 3D printed item I've bought from OOD, but this one really misses the mark.
