The 72mm White Balance Cap with 62mm and 67mm Ring Adapters from Vivitar allows you to easily calibrate your camera for color. Simply place the white balance cap over the lens and scene-specific light, combined with reflected light, is evaluated for accurate white balance. The 72mm comes with two adapter rings to use on 62mm and 67mm lenses. It is easily portable, convenient and weather resistant. An attached cord allows the cap to hang from the lens.