Two concentric tubes of cardboard or plastic surrounding an unused tampon. One inserts the tubes into the vagina, pushes up on the smaller, inside one, and it pushes the tampon itself farther into the vagina. Then one removes the applicator and throws it away. Tampax and OB Tampons both make applicator-less tampons which are inserted with just the fingers. Those work far better for me, but the one with applicators are more common, used by women who:
- are too squeamish to touch themselves
- feel that the tampon gets placed in a more comfortable or secure place when they insert it with an applicator
- are in a situation where they are unable to wash their hands after inserting a tampon.