The 8416 is a special quality double triode, the 12.6 Volt heater version of the E88CC. The 8416 was used as the front end in high quality oscilloscopes.
This envelope contains two separate valves with a screen between.
This logo looks to proclaim Premium Quality. Note the gold plated base pins.
The Tektronix box clearly shows that this valve was going to be used in an oscilloscope.
Thanks to John Sykes for sending the photographs.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 45 mm tall.
References: Data-sheet & 1040. Type 8416 was first introduced in 1965. See also1965 adverts.