This is a kit of Blichamnn's Oxygen Flow Regulator along with their inline diffusion stone setup to allow you to add oxygen to your wort inline to further prevent contamination.
The new Blichmann Engineering™ Oxygen Flow Regulator helps you dial in the EXACT liters per minute of oxygen needed to acheive 8-10 ppm of dissolved oxygen in your wort. Vital to yeast health and the final flavor profile of your beer. Knowing the FLOW is important - other regulators simply regulate pressure and depending on your downstream restriction the actual flow can vary widely. Gone are the days of spray and pray!