This gem, almost unobtanium, was designed to be a low-cost oscilloscope CRT and appeared in the RCA 151 oscilloscope. This one is probably one of the earlier units, but RCA didn't always date code things in a way you could decipher. It's packed in the original box (disintegrating) with the original paper pack material. This is a spare for my 151 scope, and goes with the 885 (in the background) posted earlier. This, along with the image multiplier I posted a week or so ago, is one of the more unusual tubes in my parts cabinet. (This post is for that special someone on Poal, you know who you are.)