Adopting CH344Q, SP3485 chips, the solution is and stable. The 480Mbps high-speed USB interface is stable, firm, reliable and compatible. Adopting USB2.0-B interface and 5.08mm terminal block, plugging and unplugging are smooth, firm and reliable. With power isolation and signal isolation circuits. The USB end is equipped with electrostatic ESD protection circuit to protect the rear circuit and equipment. The RS485 end is equipped with overcurrent protection, surge protection, and fulmination gas discharge protection circuit. The onboard 120R terminal resistance selection dip switch can increase the stability of signal mission and reduce interference. Baud rate support range: up to 3Mbps. Aluminum alloy shell, oxidized frosted treatment, precise opening, firm and , exquisite workmanship. 10 external LED indicators are convenient for checking power supply, device configuration status and signal receiving and sending status. Due to different batches, there may be differences in product appearance and printed text, which not affect use Color: black Material: Aluminum alloy Package Contents: 1 x USB serial port module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.