Lucas MA6 6v large diameter oil filled ignition coil.
As fitted to BSA A50/A65, many Triumph models and Royal Enfield Bullet 350cc.

Genuine Lucas MA6 6V ignition coils are manufactured exclusively for Wassell.
Coil clamps are sold separately as 45124C

Length : 5″
Body diameter : 1-7/8″
Voltage : 6V