B12A base
Mounting distance 44mm, chassis hole approx 38mm
12pin Duodecal tube sockets are fit for many types of cathode ray tubes (CRT) such as 2BP1, 3ADP1, 3AQP1, 3MP1, 3RP1, 3SP1, 3UP1, 3WP1, 4MP1, 5DEP1, 5UP1, photo multiplier tubes (PMT) such as 2067, 4440,6199 and DG7-32,2BP1, 3ADP1, 3AQP1, etc.