Product Description: Enhance your communication capabilities with the YINITONE RC‑108 Relay Box, a simple yet powerful solution for extending the range of your two-way radios. This handheld intercom repeater box is designed to facilitate long-distance communication, making it an essential tool for various scenarios. Long-Distance Communication: The YINITONE RC‑108 Relay Box significantly extends the communication range of your walkie-talkies by more than 10 kilometers. It supports two-way communication, allowing for both reception and transmission, ensuring you stay connected over long distances. Easy Operation: This relay box is incredibly user-friendly. It requires no power supply and no modifications to your existing walkie-talkies. Simply connect two portable walkie-talkies to the external mic/spk ports (2.5mm and 3.5mm) using the provided cables, and you're ready to go. Durable Construction: Crafted from high-quality ABS material, the YINITONE RC‑108 is built to last. Its durable and wear-resistant design ensures a long service life, while the straightforward connection process makes it convenient to use. Just connect two handheld walkie-talkies to the repeater through the earphone jack for seamless operation. Versatile Applications: This relay box is suitable for a wide range of scenarios, including: Connecting relay stations to extend signal coverage. Enhancing communication at construction sites and underground mines. Supporting emergency rescue operations in caves and culverts. Facilitating communication in V-U section relays and between small basements and ground intercoms. Providing reliable communication during large-scale events and other critical situations. Operating Modes: The YINITONE RC‑108 offers multiple operating modes to suit your needs: Transponder downlink transmission: Use machine A for uplink receiving and machine B for downlink transmission to achieve relay functionality. Two-way forwarding: Machine B receives signals while the first machine transmits, enabling two-way forwarding. Audio trigger mode: When in use, the relay box ensures the received walkie-talkie signal is at full volume for clear communication. Upgrade your communication setup with the YINITONE RC‑108 Relay Box, and experience enhanced range and reliability in all your communication endeavors. Whether for professional use or emergency situations, this repeater box delivers exceptional performance and versatility.