3.5mm speaker jack 3.5mm pin external speakers for easy installationDon't worry about the sound being affected by strong winds and waves Loud Volume High power audio output with volume up to 90-110dBDelivering clear and loud sound in rough seas for your sonic needsSuitable for docks, ports, bays, cruise ships, boats, docking areas, etc. Package includes 1 x RM20 Marine Transceiver 1 x Handheld Microphone 1 x Mounting Bracket 1 x DC Power Cable 1 x User Manual（UK DE FR IT ES） Built-in GPS Built-in GPS latitude and longitude and time, can be connected to external GPS devices.It can also send and receive latitude and longitude of other devices.Built-in GPS, GLONAS, SBAS Satellite-based augmentation system, and support multiple NMEA format transmission, very suitable for ocean navigation. Class D DSC A variety of call modes are suitable for different emergency calling needsSupport distress call, individual call, group call and geographical area callWhen in danger, press the button to send a distress call to the Coast Guard Long range High power output for longer distancesSea calls can reach 10-15 kmEnsure a strong and stable signal while sailing IP67 Waterproof IP67 Waterproof construction (1m Depth of water for 30 minutes)Vibration drainage removes moisture from speakersEffectively reduce corrosion and ensure clear sound Easy to install Can be flush mounted on the dashboardComes with mounting brackets and accessoriesSimple installation and easy operation Dual & Tri-watch Dual Watch can alternately listen to the current channel and CH 16Tri-watch can alternately watch the current channel, CH 16 and CALL channel Male antenna interface Antenna not included in accessoriesCompatible Antenna Type: 50Ω ImpedanceInstall the antenna before transmitting to avoid damage to the marine walkie talkie Priority & Normal Scan Priority Scan searches through all TAG channels sequentially while watching CH16One-click marking of all channels can achieve full scan requirements General Specifications: Antenna Impedance 50Ω Dimensions 153x152x67mm/6.02x5.98x2.64in Weight (main unit) 742g Operating Temperature -20°C ~+60°C Operating Voltage DC13.8V (+15%)