Adopts original FT232RL for USB communication, fast communicating, stable and reliable, better compatibility Onboard over-voltage, over-current protection circuits (there's no protection between the two power supplies of the host terminal).Onboard unibody power supply isolation, providing stable isolated voltage, no extra power supply required for the isolated terminal Onboard unibody digital isolation, for isolating the signal, reliable and jamproof, low power consumption.Onboard TVS (Transient Voltage Suppressor), effectively suppress surge voltage and transient spike voltage in the circuit, lightningproof & anti-electrostatic Onboard resettable fuse and protection diodes, ensures the current/voltage stable outputs, provides over-current/over-voltage proof, improves shock resistance.Onboard TTL serial port 3.3V and 5V voltage level switch, allows the user to select TTL level of the Group B terminal Aluminium alloy enclosure with oxidation dull-polish surface, solid and durable