Edwards 270-GAO Category : EST/EdwardsThis is the original version of the 270-GAO. It is essentially the same as the newer version of the EST...
Amseco BZ-51-PC2 Category : AmsecoI like the grille, or in other words, have nothing special to say about this particular unit.
GE 521BXT Category : GEI think that this smoke detector might be intended for use in security systems.