Statista notes that the most popularly brands of tampons used by U.S. households, from 2011 to 2013, include Tampax, Playtex, Kotex and O.B. Not all women find the same brand and style of tampon to be equally comfortable; therefore, tampons are available in a variety of sizes and applicator styles.
According to the Women's Health section of About.com, cardboard applicators are the least expensive and the most environmentally friendly. Plastic applicators are sometimes easier and more comfortable for women to use. Some tampons do not include applicators at all; these are called digital tampons.
The About.com Women's Health section explains that tampons vary in the amount of fluid that they can absorb, and they are labeled accordingly. The absorbency rating system helps women to decide which tampon is right for their flow-level. For example, tampons labeled "Regular" hold 6 to 9 grams of fluid, and tampons labeled "Super" hold 9 to 12 grams of fluid.
The Palto Alto Medical Foundation recommends that women use the smallest absorbency possible for their periods, and never use tampons when they are not menstruating. The Tampax website states that tampons can be worn overnight, but a tampon must not be worn for longer than eight hours.