Round Filter for InchekTM, InCheck DIALTM, MultispiroTM, Creative Biomedics,Vigtaloraph,Schiller,MicroDirect, SDI,(PulmogardIITM), Most Cosmed Models,MIR (AllModels), P.K.Morgan 232, Future Med(Spirobank), PB-400,PB-600,CDXSpiro 850,Spirometrics (Flowmate,Flowmate+), SMII,Vacumed (MicroPlus,Micro GP-GL,Micro Loop,Pony)