Scuba Tank Handle

I was inspired by @jangrewe who produced his scuba tank handle, see here → https://www.printables.com/model/1062029-scuba-tank-handleHowever I guess scuba tanks come in all sizes, my wife has two tanks and they both have a neck diameter of 40mm so I decided to model and print one for her.Given that there could be subtle differences between scuba tanks (paint, stickers, etc.) and printers and filament, I decided to provide a few very slightly differently sized collars. Print the handle, and pair it with one of the collars:40mm inside diameter40.5mm inside diameter41mm inside diameter41.5mm inside diameterThe naming of the files should make clear which one is which.For connecting the parts together, you'll need:2 x M6 x 35mm bolt and nut1 x M6 x 80mm bolt and nutFor the bolts I went with hex head inserts as I know that the divers my wife dives with all have hex keys as part of their little toolkit.When printing, I chose to use 25% infill, 6 wall loops and 5 layers bottom and top. For