Datasheet for the Simplex TrueAlert Non-Addressable Notification Appliances for 4-Wire Operation, published in 2014. Document No: S4903-0011-6, Rev: 11/2014. 24 models including 4903-9425, 4903-9426, 4903-9427 and 21 additional variants. Engineering specifications, wiring diagrams, and mounting dimensions.