The product is a lot of 20 Finisar FTCD4313E2PCLFBE 400G QSFP-DD FR4 13XX nm 3km SMF transceivers. These transceivers are designed for optical fiber networking and are suitable for high-speed data transmission. With a SFP connector and compatibility with the specified model, these units are ideal for computer networking and connectivity applications. Manufactured in China by Finisar, a reputable brand in the industry, these transceivers offer reliable performance and efficient data transfer.