Eppendorf 2ml Cryo Tray

Not quite ready for the spotlight, this tray has been uploaded to share for a collaboration. It's intended to secure 5 Eppendorf tubes for a liquid nitrogen bath. The tray can then be transferred to a freezer or dry ice. Trays can be connected for shipping.
The trays can be secured top-to-bottom by threading onto a 1/4"-20 carriage bolt and then fastening the other end with a fender washer across the top of the sample tubes, followed by a spring or split washer, then a wingnut. Pictures and better instructions when I'm done, promise.
Future changes: A generic version without embedded labels. A printed pentagonal washer and spacers. Less material, more efficient layout, and better venting for LN2.