New old stock Sylvania 6S4A vacuum tube.  Medium-mu triode rated 8.5 watts plate dissipation.  Made in USA.

Shipping can be combined with my other tubes, sockets, and parts for sale on my ebay store, $0.50 for each additional miniature, $1 for each additional octal.  Add to cart then request invoice.
While stock is available, I will attempt to meet brand or sub-type requests that do not require detailed inspection.  Some types have additional stock available.