The 6AQ5A is a small audio output beam tetrode valve capable of 4.5 Watts in a single ended configuration. The A variant indicates a controlled warm-up time.
The RCA Logo.
RCA in large letters.
Made in USA.
The thin glass tube envelope is 18 mm in diameter and excluding the B7G base pins, is 58 mm long.
References: Data-sheet & 1040. Type 6AQ5A was first introduced in 1958. See also1958 adverts.