It is a PT334-6C 5mm Phototransistor. PT334-6C is a high speed and high sensitive silicon NPN epitaxial planar phototransistor in a standard 5Φ package. Due to is water clear epoxy the device is sensitive to visible and near-infrared radiation. Package Includes: 10 x PT334-6C 5mm Phototransistor. SKU: PGI-00616275 Category: Light/Color Sensor