This is Unflavoured PG Propylene Glycol E liquid Base without Nicotine, suitable for making an individual DIY E-liquid and other uses. You can mix it with VG Base, where most popular ratios are PG/VG 30/70, 50/50 and 70/30.
Propylene Glycol is available in 120ml, 500ml, 1L and 5L sizes.