The B10B base was introduced by Philips/Mullard for the PFL200 all glass double pentode valve. These were used in television receivers from the mid 1960s. The B10B represented the end of the road for the number of pins built into a base for mass produced valves of 20-21 mm diameter. The American Compactrons used 12 pins (B12C) and included up to three sections in a wide envelope. Special devices and CRTs did employ more pins as required.
Typical use was as frame generator and frame output valve in a single envelope. Also as a video output valve and inter-carrier sound amplifier.