LTAR Lens Barrel Adapter (d33mm x f96mm)
This component will fit a plano-convex lens, 33mm in diameter, and 96mm focal length. When installing this in an LTAR, you will have to open up the existing focus tube and remove the stock emitter lens.
When going to print, choosing cm as your unit should get you the proper scale. If you find it out of scale, make sure you have chosen a metric option, and then you should be able to just scale it by some factor of 10 to get envelope dimensions around 4.5x5x14ish