The Posi-Vac Non-Rebreathing System is used with an in-house vacuum to greatly reduce waste anesthetic gases from the workplace. It includes a Mapleson-D style body, lab animal anesthesia nosecone with incisor bar and waste anesthetic gas collecting shroud. The Posi-Vac Non-Rebreathing System comes in three sizes and each of the nosecone / shroud on the Mapleson-D style body. Each size also has incisor bar.