This is a matching pair of 2 vintage BRIMAR "made in England" 13D2 tubes.  The 13D2 is a premium mil-spec version of the 6SN7GT.

They appear to be new or almost new and test as such.  Circa late 1950s production. These are a very rare version of the 6SN7 type.  Have two 00 top getters and offset grey plates. Brown bases - one is a little darker than the other and has no writing on the base.  Tested for emission and shorts with an AVO 163 tester and  FULLY MATCHED both side to side and as a set of four using a modern CURVE TRACER.  

FREE post to anywhere in the world.

See my other listings for more vintage and modern tubes as I clear my 30 years collection of vintage audio.