I present my triple tritium decorative bead, designed to take three of the 2x12mm tritium vials (tritium vials not included). Alternatively, to achieve a greater variety of colour; six 2x6mm tritium vials could be installed instead.
The central hole is 5mm in diameter and should just be wide enough for two lengths of 550 paracord.
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.