(AE111) Aeration is beneficial to your wine because it supplies yeast cells with oxygen needed for reproduction and healthy fermentation. The Aeration system is an efficient, sanitary and inexpensive way to aerate the wine in the primary fermenter. The pump forces air through the sanitary, in-line HEPA filter which removes dirt and contaminants. The air is then delivered to the wine through a stainless steel diffusion stone, which promotes rapid absorption into the wine. For best results, aerate your wine 15 - 20 min prior to adding your wine yeast. Carboy and stopper not included.