The VR59 (later renamed as CV1059) is an acorn triode. The prototypes were the 955, HA2 and 4671.
The American Government Vacuum Tube codes are VT-nn whereas the UK format is VTnn in this case Raytheon has added the hyphen to a valve made for the UK.
The triode section is tiny. The side pins result in both low inductance short leads and seal breakages when not using a zero insertion force base.
The old stores code of 110E/40 is also etched into the envelope - indicating that this American valve was made for RAF use.
The acorn envelope is 14 mm in diameter and, excluding the base pins, is 34 mm tall.