Diodes Inc. MMBT3904-7-F is a NPN BJT transistor for switching applications. Features include VCEsat of 0.3V, hFE of 30, and IC of 0.2A. With a max operating temp of 150°C, it's ideal for small outline SMT designs in automotive electronics.
SSL-LXA228SRC-TR11 by Lumex is a 1.9mm SINGLE COLOR LED with peak wavelength of 660nm and max forward current of 0.03A. Ideal for applications requiring SUPER RED light emission, such as indicator lights in electronic devices due to its clear lens and surface mounting feature.
ULN2803A by Texas Instruments is a peripheral driver with 8 functions. It has a max supply voltage of 3V and can operate in temperatures ranging from -40 to 85°C. This IC is commonly used as a buffer or inverter based peripheral driver for various applications.