The CAP ALUM POLY 150UF 20 4V SMD capacitor is a type of aluminum-polymer capacitor designed for radial and surface-mount applications. It has a capacitance value of 150 microfarads (µF), operates at a voltage rating of 4 volts, and features a small surface-mount design (SMD). This component is constructed with an aluminum and polymer material combination, offering reliable performance over extended periods, specifically up to 2000 hours at a temperature of 105°C.