The top to some random clear filler type carto and a tube of metal from a e cigar bought is some gas stations. I measuring tape and a pipe cutter. And a nib of superglue around the inner top to secure metals together. The fun part the pipe cutter kind of "tucks" the cut end allowing for a way for you secure in place on the vision (on the lower end) and yet remove if needed. Just love my drip tips as much as the giant. Thank you girls for asking. <3