The 66158-011 from Micropac Industries is a Space Qualified Optocoupler with Forward Voltage 1.2 to 1.5 V, Isolation Voltage 500 V, On-State Collector Current 2 to 20 mA, Power Consumption 230 mW(Power Dissipation), Resistance 10 Ohms. Tags: Through Hole. More details for 66158-011 can be seen below.