This build was in an old green laserpen. It has brass wall as you can see in the first picture in the junkbox. The tube has some black paint scrap off and beneath you see the brass metal.
I have noticed the newer green laserpens are much lighter in weight and the material is different. Also in the first picture on the top there is a silver penhost made of this material.
EDIT* I guess this one has a lense, the G2, which I have read is pretty good. but is very expensive. Any alternatives for cheaper?
2nd Edit* I guess the 2nd link has an included driver as well. It includes the 1.8A X-Drive and the 405-G-2 already installed. It is sold by DTR, which I have already been recommended to check out by another member, so I think it looks like an ok deal?
It looks like your found DTR's listings. His website has quite a few more options. The different diodes he sells as well as combinations can be found here. You can purchase it with the driver and a 3-element lens which is cheaper. The 3-Element isn't as good at burning as the G2 but it has less beam divergence.