Features Can be used for: telecommunication engineers, wiring engineers and network maintenance engineers, etc. Cable classification is the process of detecting physical connections in cables such as open circuits, short circuits, faulty circuits, and reverse circuits. Use the transmitter to detect line level or positive and negative. There are two ways to detect the connection status of a circuit. It is suitable for directly looking for cables with RJ45 connectors, telephone lines with RJ11 connectors. Features:  -Can be used for: telecommunication engineers, wiring engineers and network maintenance engineers, etc. -Cable classification is the process of detecting physical connections in cables such as open circuits, short circuits, faulty circuits, and reverse circuits. -Use the transmitter to detect line level or positive and negative. -There are two ways to detect the connection status of a circuit. -It is suitable for directly looking for cables with RJ45 connectors, telephone lines with RJ11 connectors. Specifications:  Work Temperature:0~40℃,the maximum 80% relatively humidity (no coagulation) Storage Temperature:-10~50℃, the maximum 80% relatively humidity (no coagulation,no battery) Elevation: ＜2000 meters Type of Anti-explosion: IP 40 Distance of Sending Signal: ＞3000 meters Battery: 3x1.5V/AAA (Emitter), 1x6F22/9V (River)(Battery not included) Item Color: Green RJ45 Cable Length:16.8cm/6.6in Weight: Approx.360g/12.7oz   Package list: 1 * Emitter (Battery is not included.) 1 * River (Battery is not included.) 1 * crocodile clip test line 1 * user manual 1 * RJ45 cable (random color) 1 * cloth pouch 1 * Earphone Package List