... usb hub,4 ports usb 2.0 hub,USB extension device high speed usb hub,4 ports usb 2.0 hub ... indicator6. Work humidity: 10% - 90%7. Working voltage: 5V8. Working current: 500mA7. Working temperature: - 20c - 75C8. Storage temperature: -40c - 85C9. Support ... high-speed transmission, decentralization in USB 1.1Train without driver, plug and play, support hot swapsTrain USB 2.0 equipment support ...