Radium Engineering AOS-R - Universal VTA (Vent to Atmosphere)The Radium Engineering AOS R (Air Oil Separator Recirculating) is a precision engineered crankcase ventilation solution designed to separate oil vapors and contaminants from crankcase gases before they enter the atmosphere. This universal VTA (Vent to Atmosphere) configuration features advanced internal baffling, CNC machined construction, and a compact design suitable for a wide range of applications where clean venting is required. Part Number 20