bc303The BC303 is a bipolar junction transistor (BJT) with an PNP-type confuration. That means the BC303 transistor has a negatively charged layer between two positively charged layers. ThisBC303 datasheet PDF download, CDIL Transistors - Bipolar (BJT) - Single, Pre-Biased BC303 Specifications: Transistor: PNP; bipolar; 60V; 0.5A; 0.85W; TO39.