The FAIRCHILD offers a two different models of Selector Relays purposed to cater different applications. Both of these models are suitable for dead end or minimal flow service in critical operations. The Model 90 is a low pressure selector relay which is constructed to pick the lower of two signal pressure. This is done to grant an uninterrupted output pressure to manage a device. It is applicable for working with control loops which necessitate for an accurate monitoring of signal pressure. The Model 91, on the other hand, is a high pressure selector relay which is made to select the higher of two signal pressure. It is integrated with the capacity to accurately control pressure shifting and various monitoring functions.