It features. Directly heated Thorogate in tungsten filament for soft glow and warm sound. 

Hard glass envelope with white ceramic base.

 Low microphonic construction with ceramic internal spacers.

Graphite plate with titanium coding for extremely high power capability and inherent gathering. Superb aesthetic appearance. 

The SV 5 72–1 60 has a plate dissipation of 125 W maximum.

 It is intended for audio applications or triodes of the 811A type are normally used while giving superior performance.

See attached photos for more information and detailed data.