18 mm; overall column height 155 mm. Excellent Condition with slight surface rust on metal struts (Photos 5 & 6) & split in leather cover (photo 9) from storage. VISIT MY STORE FOR MORE NOS BRITISH MADE PARTS FROM LUCAS, CAV, BUTLERS, WILMOT BREEDEN, SMITHS, JAEGER for the most period british car like AC Cobra, A. N, ALVIS, Allard, Aston Martin DB2, DB2/4, DB3/S, Austin 8 10 12 16, A30, A35, A40, A90, A50, A55, A125, A135, Civilian CHAMP, Healey, 3000, Sprite, Frogeyd, BENTLEY, BRISTOL, Delow, Daimler, Hillman Super Minx, HUSKY, Isetta, Jaguar 2.5 litre, 3.5 litre, XK120, Lotus Mk. IX, MG Midget MGA MGB TC TD TA, Morris Minor 1000, MINI Cooper S 1000 Clubman, Reliant, Landrover Military or Civilian Series one 1 2 3, Singer 9, 4AC, 4AD, SM1500, Triumph TR2 TR3 TR6 TR7 Herald, STAG, 1300, 1500, BEDFORD, FORD Escort Cortina MkI MkII Capri Zephyr Zodiac and more other period cars.