These Specula will NOT work with the new 4rth generation or 5th Generation Dr Mom Otoscopes. These specula are specifically built for the Doctor Mom Original and Third Generation Doctor Mom Otoscopes. Please pay close attention to the model otoscope you are buying them for. With an active infection specula help to lowers risk of ear infection transmission from one ear to another or from one person to another These specula are specifically built for the Doctor Mom Original and Third Generation Doctor Mom Otoscopes. These Specula will NOT work with the new 4rth generation or 5th Generation Dr Mom Otoscopes.