Test Tube Mezuzah

I have always been partial to mezuzah cases where you can see the klaf.

What I particularly like about this design is that you can easily remove the test tube from the rest of the case when you take your mezuzot to the sofer to get them checked – you can take the entire test tube with you, and never have to touch the klaf yourself.  And then reinsert the test-tube just as easily.

I bought these test tubes, but any 20-mm diameter test tube should work.