Two pre-biased NPNs in one tiny package
The Toshiba RN1908(T5L,F,T) packs two NPN pre-biased transistors into a 6-pin SOT-363 package (also known as SC-88 or US6). The 250 MHz transition frequency means it handles switching and small-signal amplification well into the low-VHF range, not just on/off relay driving.
The 200 mW total power limit across both transistors means you need to keep the junction cool — in a dense board with no airflow, stay well below 50 mA per side if both are on continuously. The 300 mV saturation voltage at 5 mA collector current and 250 µA base drive is typical for a pre-biased part; if you need lower headroom, a non-biased transistor with a tighter base resistor network might be a better fit.