Nutone IS-305wh inside intercom station

hi today we're going to go over an often misunderstood feature that has to do with these two intercom remote stations and the systems that they're connected to so over here on the Left this is a new tone is 405 and the is 405 is used with the I M and the IMA 4006 intercom system and here on the right we have an is a four four five and this is used with the i m and the IMA 4406 system and while these two speakers look very different they're actually almost identically the same they look very different because this grille style was in use between 1986 and the end of 1995 and this grille style was used in 1996 through the end of about 2008 so cosmetically they are different however from a functional point of view there are exactly and identically the same and they are also interchangeable you could take is a 4 4 5 s and use them with a four thousand six system you can take an is 405 and us