Electronic Supply by Industrial Electronics in Milwaukee Wisconsin : Potter Brumfield, Radio Shack Stores in Milwaukee: When Size Is a Consideration When Size Is a Consideration ================================================================================ Staff on 23/12/2009 20:33:00 The Mallory Sonalert MSR Series is a piezo-ceramic product which was developed to combine a smaller size (23mm Dia. x 10.5mm Hgt.) with a high audible output. Like the standard-sized Mallory Sonalert, it is a self contained piezo device. Electro-magnetic devices, which create deflections in the base material via a magnetic field, can be made smaller than piezo-ceramic devices, and are frequently employed in small or miniature consumer devices. One drawback of these products is that they do not create as much audible output and are not as capable of creating as many different types of continuous and intermittent sounds. However, depending on the application, this may not be a negative.