The OCIC CYTLP291(GB-TP) Optocouplers - Phototransistor Output ROHS is a 4-Pin package optocoupler that contains a phototransistor output, as well as additional components. This optocoupler is used to isolate and protect input control signals from the output circuit, allowing greater noise and EMC immunity. Other features include a low input current, high collector-emitter voltage, and low output saturation voltage. The optocoupler is RoHS compliant and is suitable for a variety of industrial applications.