Patchouli Dark is high grade, pure, uncut, dark Indonesian patchouli oil. Dark patchouli oil is patchouli oil, when distilled is stored in cast iron vessels as opposed to neutral vessels like stainless steel, glass, ceramic, etc. The iron reacts with the oil to not only darken the color but also to alter the fragrance. The patchouli oil becomes deeper, softer, earthier, sweeter, much less "hot" and aggressive to the nose. Since it is uncut, take care when applying it directly to skin as some may react to pure patchouli oil, so go easy at first. We pour out two sizes, half ounce (15ml) and sixth ounce (5ml) It comes with a dropper insert for easier application. We buy decent quantities at a time and fill the little bottles ourselves so we are able to offer such quality and quantity at this price.