Retevis NR40 DMR Digital and Analog Two-Way Radio Communicator - Long-range, rechargeable, heavy-duty, durable adult-sized radio for factory managers, workshop production personnel, construction project production and dispatchers, warehouse and logistics dispatchers, and high-noise scenarios such as concerts. Function: Long range walkie talkie; concrete buildings often make the signal of the walkie talkies attenuation; and the NR40 2 way radio is specially designed to deal with the high output power of the communication in the building; so that the information can be effectively and clearly conveyed over long distances. Clear sound quality; NR40 walkie-talkie uses DMR technology; unlike analog radios; its sound quality does not deteriorate with distance; even at the edge of the signal;.