The OP800C from TT Electronics is a Phototransistor with Collector-Dark Current 100 nA, Collector Emitter Voltage(Saturation) 0.40 V, Emitter Collector Voltage(Breakdown) 5 V, On-State Collector Current 0.9 to 3.6 mA, Power Dissipation 250 mW. More details for OP800C can be seen below.