Bulb, Blinker/Parking/Tail light Lamp, MGB, 2 filament
This is a 2 filament bulb, used in 70 - 80 MGB for front blinker/parking lamps, and for the tail light/brake light in the rear lights 62-80. Some MGBs used a single, two filament bulb in the front blinker/parking lamp, this is the bulb for that. There are some variations in reproduction lamps.
Some use two separate single filament bulbs, a small one for the parking light, and a larger for the blinker light (170-250 and 170-800).