(!!!) (#2 19J6 Pair) 9J6 RCA NOS 1950's - 1960's same internal plate structure, different getter halo shape1 matched pair) 19J6 RCA NOS 1950's 1960's same internal plate structure, different getter halo shape 1 tube) 38 43 27 "U" getter halo RCA rebranded GE 1950's 1 tube) 37 45 27 "O" getter halo RCA Millett Starving Student Hybrid (all made by RCA and can be rebranded various names like Sylvania, Ken Rad, etc.)