SFH 309 FA-5 - 

Phototransistor T-1 (3mm) Package
This family of NPN silicon phototransistors, from OSRAM Opto Semiconductors, are a range of 3mm (T-1) through-hole devices. They have both clear or black plastic lenses, the diffused lenses being used for daylight filters. Suitable applications include; photointerrupters, industrial electronics and for control/drive circuits.