Note: Bulb size or diameter (maximum) is expressed in an eighth of an inch (1/8") for one unit. For instance, a BT56 bulb is 56 eighths of an inch in diameter, or 7 inches in diameter. See ANSI C79.1 for complete details on bulb shapes.
Lamp Maximum Overall Length (M.O.L.):*
MOL is measured from the end of the lamp base to the top of the outer jacket.
Light Center Length (L.C.L.):†
The distance from the light center to a specified reference point on the lamp.
The diameter is the maximum diameter of the glass bulb.
Arc Tube Maximum Overall Length (M.O.L.):*
The distance between the ends of the bases.
Contact to Contact:
The length between contacts is the distance
between the metal contacts which
are recessed inside the ends of the bases.
The approximate diameter of the tube.
* Not a controlled dimension - can vary ±10mm
† A controlled dimension - can vary ±3mm