VG50/PG50 Base 9mg. - 10ml.
If you only want 10ml of PG/VG base with 9mg nicotine, you can simply unscrew the lid and then add up to 2ml of aroma (20%) directly into the bottle. Then shake the bottle. It's easy!!
The liquid should ideally mature for a few hours/days before use.
Normally, pg/vg bases are mixed with about 10% Aroma (which is pg based) to add flavour.