[Leica] How do I screw in a magnifier

[rbaron at concentric.net (Robert D. Baron)]

I went to a hardware store....the department where keys are made.....I 
bought a colored rubber or plastic round thingy that fits over the head 
of a key....it fits over the end of my eBay Hong Kong 1.25x magnifier, 
thus protecting my glasses....it will be hard for it to slip off, and 
they are cheap and come in a wide range of colors.

I'll bet they sell them in key shops, too.

--Bob