The emission of hydroxyl megamasers occurs predominantly in the so-called "main lines" at 1665 and 1667 MHz. The hydroxyl molecule also has two "satellite lines" that emit at 1612 and 1720 MHz, but few hydroxyl megamasers have had satellite lines detected. Emission in all known hydroxyl megamasers is stronger in the 1667 MHz line; typical ratios of the flux in the 1667 MHz line to the 1665 MHz line, called the hyperfine ratio, range from a minimum of 2 to greater than 20. For hydroxyl emitting in thermodynamic equilibrium, this ratio will range from 1.8 to 1, depending upon the optical depth, so line ratios greater than 2 are indicative of a population out of thermal equilibrium. This may be compared with galactic hydroxyl masers in star-forming regions, where the 1665 MHz line is typically strongest, and hydroxyl masers around evolved stars, in which the 1612 MHz line is often strongest, and of the main lines, 1667 MHz emission is frequently stronger than 1612 MHz. The total width of emission at a given frequency is typically many hundreds of kilometers per second, and individual features that make up the total emission profile have widths ranging from tens to hundreds of kilometers per second. These may also be compared with galactic hydroxyl masers, which typically have linewidths of order a kilometer per second or narrower, and are spread over a velocity of a few to tens of kilometers per second.