BSA
Genuine Lucas L564 Tail Lamp Light Assembly with Stop and Tail Bulb.
Printed on lens: REGD DESIGN BS 2516 GRADE 1
LUCAS REFLEX BS 2515 GRADE 2
LUCAS L564 MADE IN ENGLAND
Originally used on BSA B33 1954 with 6V stop&tail lamp but now fitted with 12V to test.
Not as-new but serviceable (see photos for condition).