Our oils are all bottled in-house, and so quality control extends to the point of despatch. The oils are supplied in brown glass bottles with oil resistant labelling. The black labels with gold writing include the common and botanical name, true to species, the country of origin and quantity. 5ml & 10ml quantities are supplied in a 10ml bottle as this best fits the boxes, and suits most therapists. We are able to supply 5ml quantities in 5ml bottles if you prefer, but please specify this when ordering. The insert (dropper) is designed to give the optimum flow for the density of the oil supplied. The inserts we use are known as vertical droppers and are designed to be used with the bottle completely inverted. Lead time (first drop) may be a little slow, but subsequent drops are faster. They do not work well if the bottle is simply tipped. We use a variety of inserts and so if you find the flow too slow, or too fast we may be able to supply a different insert on request.