This document provides specifications for an EC31S09VN4 loudspeaker membrane basket assembly. Key specifications include: 1. The assembly uses a neodymium magnet that is 18.5mm thick and has a diameter of 31mm. 2. It has an impedance of 4 ohms, a power rating of 3.5 watts, and a resonant frequency of 250Hz. 3. Additional specifications cover dimensions, sensitivity, frequency response, total harmonic distortion, storage temperature, polarity, and testing results for rub and buzz, insulation resistance, temperature ranges, and humidity.