The 66296-301 from Micropac Industries is a Space Qualified Optocoupler with Forward Voltage 0.8 to 1.8 V, Isolation Voltage 1000 V, On-State Collector Current 2 mA, Power Consumption 300 mW(Power Dissipation), Capacitance 5 pF. Tags: Surface Mount. More details for 66296-301 can be seen below.