Multi-Functional: Features include open circuit and short circuit testing, telephone wire detection, cable tracing, DC level testing (DC 3–10V), network line detection, and network cable verification. Low Voltage Prompt: When the transmitter's function switch is set to find mode and the battery voltage drops below 6V, the "SCAN" LED and "line sequence" LED will flash simultaneously to indicate low battery. Earphone Function: Includes earphone support for use in noisy environments to reduce external interference. Spotlight Function: Built-in light allows for easy operation in dark or low-light conditions. Volume Adjustable: Adjust the volume knob on the receiver to control sound level and sensitivity. Energy Saving: Automatic power-off function delays shutdown approximately one hour after startup. Specifications: Product Name: Network Line Finder Product Model: M469A Battery: 6F22 9V battery (not included) Interface: RJ11, RJ45 Transmitter Dimensions: 127 x 56.5 x 30 mm / 5 x 2.22 x 1.18 inches Transmitter Weight: 62g / 2.19oz Receiver Dimensions: 198 x 46 x 31.5 mm / 7.79 x 1.81 x 1.24 inches Receiver Weight: 77g / 2.72oz Material: ABS Color: Black Package Contents: 2 x Tester 1 x RJ11 Clip 1 x RJ11 Test Cable 1 x RJ45 Test Cable 1 x Storage Bag 1 x Headphone Note: The package includes only the items listed above. Other accessories shown are not included. Note: Lighting and display differences may cause slight variations in color between the image and actual item. Measurement error is +/- 1-3cm.