BG and an unbranded item.
One side has the letters BG inside a six point star. The other side states 'Made in England".
As with most of these adaptors, the red button is pressed for ON, the black button for OFF.
The plug pins are single piece brass items.
The shade ring is missing.
The plug pins on this one are formed from the heads of two brass screws.
Shade rings were frequently lost or broken, as the heat from the lamp made them brittle.