Roller Ball Bottles for Perfume or Massage Oils – use these glass cobalt blue bottles (sold in sets of 4) for applying small amounts of perfumes or massage oils. These cobalt blue bottles with roller ball tops make great gifts or you can use them for your own personal perfume. Just add a few drop of essential oil or essential oil blend to a carrier base or alcohol base and carry it with you in these lipstick sized bottles. Size = 0.35 oz. with black top. Sold in sets of 4.