Insert the helmet slot adapters into the slots on each side of the helmet until they snap into place. When in use, the attachment arms must be pushed inward until you hear a click on both sides, indicating a shift from "stand-by" to "usage" position.
Position the earcups over your ears so that the cushions fully enclose the ears and seal tightly against the head. Adjust the position of each earcup while holding the helmet in place until you have a tight and comfortable fit that exerts even pressure around the ears
Make sure the cups and attachment arms are not in contact with the inner lining or the edge of the hard hat when in the "usage" position, otherwise this may lead to leakage.