Features: 1External earphones are used to isolate noise. If the environment is noisy during line hunting, you can bring earphones for monitoring. 2The volume can be adjusted according to the environment, and the volume can be easily controlled by turning the dial lightly. 3With receiver light, without fear of the dark environment, easily solve the trouble of dark area operation in the construction site without light source. 4The product has a high?standard line interface, you can find the line on and off. 5Widely used in a variety of situations, such as engineering wiring, computer room maintenance, etc. Package included: 2 x Host (Battery Not Included) 1 x R11 Clamp Cable For Testing 1 x RJ45 Network Cable For Test Line Sequence 1 x Test Dedicated Headset 1 x Portable Cloth Bag 1 x Manual