Max.operation temperature: -55C to +105CNotice: Because of the screw holes, these 5Pcs Male and 5Pcs Female connectors don't fit each other.This DB9 9Pins dual row connector, pcb surface mount, used as computer communication interface.Pin 1 CD Received Line Signal Detector (Data Carrier Detect)Pin 2 RXD Received DataPin 3 TXD Transmit DataPin 4 DTR Data Terminal ReadyPin 5 GND Signal GroundPin 6 DSR Data Set ReadyPin 7 RTS Request To SendPin 8 CTS Clear To SendPin 9 RI Ring Indicator