*3.3V with 5.0V power supply perfectly compatible. *3.3V with 5.0V signal perfectly compatible. *Operating temperature : -40 ? ~ + 85 ?. *Size:42.8mm * 15.22mm * 0.8mm . Features: *With RXD, TXD signal lights. *Transmission distance up to kilometers. *Absolute adopts imported chip, industrial design, strong anti-interference ability, at the same time more effective lightning protection design, 485 can be used in industrial field and field under the harsh environment. ?Using 850 meters with 2 * 1.5 cable to do the test, it is recommended to be used within the 800 meters, more than 800 m, please add extra repeaters). *Use half hole process design, thickness of 0.8 mm, can be used easily as a child motherboard, also can be used welding terminals. *With a standard 2.54 spacing design, convenient your secondary development. *With 120 European match resistance, can make short sub R0 can match resistance, proposed the short answer the long distance transport. *Support multiple machine communications, allowed to take in up to 128 devices on the bus. *This module can be hot plug, there will be no other 485 chip hotplug phenomenon of signal switch to death. *Large area laying copper, preventing signal interference. Feedback: We greatly appreciate your POSITIVE feedback. Please do NOT leave negative feedback without asking for help. Our aim is to provide Top Level Customer Service, so we will try our best to solve any problem.Thank you very much!