Probably one of the rares ECC82 12AU7 Tubes ever made. Ultra Rare welded long plates with Copper D getter with Flat Crossbar. Extremely characteristic sonics with a soft toned down but crisp top and warm and solid lowend. Very very nice to listin to. The tube has been tested on an AVO-CT160 and this valve tested like new. 

Test characteristic: 
Bottem code : K6a ◇6
Getter: D getter with Copper Flat Crossbar 
Plate: Welded

Test results: 
IA = 11/10,7 (100% = 10,5)
MA/V = 2,0/2,2 (100% = 2,1)

So the tube is in NEW / NOS / NIB condition!