This DAC toilet rim block set delivers effective cleaning, hygiene, freshness and limescale elimination. It keeps your toiled clean and fresh for a long time. The fresh burst of eucalyptus scent helps eliminate unpleasant odors. Effective Results. For best results, make sure that you place the set of these DAC fragrance blocks in the flow of water. Whenever you flush the toilet, these blocks will exude fresh smell and maintain the cleanliness of the bowl.