Original VALVO H410D used tube
Screen-grid Tetrode
H410D B442 DZ2
the tube is closed to TELEFUNKEN RES094
made by VALVO in Germany in 1930's
The tube is used, tested with the great more than 100% result:
Ia = 5,8mA
where 100% for the new tube is 4mA
screen metal painting is scratched here and there as you can see at the pictures
and there are signs of non-original glue around the base but the tube is still in great electrical shape.
the tube has Europe 5-Pin base O5A B5
you will get the tube you can see at the pictures
I always send the tubes by priority registered mail with tracking number within hours after receiving payment