The OP301SL from TT Electronics is a Phototransistor with Collector Emitter Voltage (Breakdown) 15 V, Collector-Dark Current 1 µA, Collector Emitter Voltage(Saturation) 1.1 V, Emitter Collector Voltage(Breakdown) 5 V, On-State Collector Current 0.8 to 2.4 mA. More details for OP301SL can be seen below.