Click stops are a feature of lens aperture controls where the aperture mechanism moves through a series of preset settings, each "clicking" audibly into place at its numbered f-stop. This allows photographers to quickly and accurately select the desired aperture for consistent exposure and depth of field. Click stops are especially useful in manual lenses and professional photography, as they provide tactile feedback, precise control, and repeatable results when adjusting exposure settings for portraits, landscapes, or studio work.