I present my "Triple" tritium decorative bead, designed to take three 2x12mm tritium vials (tritium vials not included). Alternatively, to achieve a greater variety of colour; six 2x6mm tritium vials could be installed instead, as shown in some of the photos.
The bead is designed to screw onto Pandora bracelets, which prevents it slipping off, when the bracelet is undone. The bead has two short threaded sections; one close to each end of the main hole. These allow the bead to be retained in position over either of the two short threaded pieces, on certain Pandora bracelets and act as a "clip".
The tritium vials 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.
There are some more photos of this object and other examples of my work, both 3D printed and otherwise, on my 'Tofty' facebook page