"A" Bulbs are the most common general purpose incandescent light bulbs in use today. The "A" designates that the shape of the bulb is ARBITRARY, the number following the "A" denotes the width of the glass envelope in eighths of an inch. A-19 bulbs are nineteen (19) eighths of an inch in diameter or 2.375" inches or 60.325 millimeters. These new LED A19 light bulbs have the shape we've all grown accustomed to with all of the advances that LED technology has to offer; lower power consumption, longer life and reduced heat production.
