I present version 2B of my keychain tritium lantern for use with a 3x22.5mm tritium vial (tritium vial not included) and does not require a clear tube like my first version.
The attachment hole is 2mm wide and is perfect for a 10mm split ring (not included).
The tritium vial should be set using a UV activated optically clear adhesive such as Norland 61 or Loctite glass bond. These adhesives will cure in direct sunlight in an hour or so.
I have a few assembled tritium lanterns in stainless steel available from my Etsy shop
(tritium vial glued in place with Norland 61 and split ring installed).
There are some more photos of this object and other examples of my work, both 3D printed and otherwise, on my 'Tofty' facebook page