Up for sale here is this set of 4 used vintage National metal J-slot tube shields, from the 1950s or 1960s and Made in USA. These are for 9-pin tubes, and will fit a 12AU7 or similar tube. These are in good shape with light to moderate wear and some light corrosion.  They measure about 2" tall and 1" in diameter.  Please see my pictures for details.

All my tube covers are listed; I don't have any available that are not listed.

US shipping and handling is $5, and international is $18, no matter what quantity you buy. All my small parts are set up for combined shipping, so just use the "add to cart" feature and then check out all at once, and it will combine shipping. If you have any questions, please ask.

I have more tube covers and other vintage electronics listed--feel free to take a look!