The Small Animal Restraints hold the rodents in Lexan restraint tubes that feature precision machined Positive Flow By nose pieces.  When placed in the chamber ports, the nose pieces connect with an o-ring seal to the inlet plenum of the chamber body.  A second o-ring seals the nose pieces to the exhaust plenum of the chamber.  Each nose piece has a series of exhaust jets strategically located behind the nose of the rodent.  While in operation, each rodent receives a fresh, continuous stream of the aerosolized test article.  The aerosol stream is drawn past the animal’s nose and into the exhaust jets where it is finally directed into the exhaust plenum of the exposure chamber.  This design completely eliminates the possibility of re-breathing by the rodents.  With the In-Tox Products Small Animal Exposure System there is no possibility that the rodents can breathe any test article exhaled by a rodent in an adjacent port.