Caprylyl Methicone

A clear, colorless, low viscosity, volatile (does not absorb into the skin but rather evaporates from it) silicone fluid that has excellent spreadability and leaves alight, silky and smooth feel on the skin.

According to manufacturer info, its big advantage is that it's compatible both with other silicones and with natural plant oils, so it's a great ingredient to formulate products with good-sounding, consumer-pleasing vegetable oils but still maintain a cosmetically elegant, non-greasy and non-tacky feel.