Feature: 1. Ultra‑compact Class D fixed installation VHF radio, dual receivers, independent DSC dedicated receiver. Supports manual input of GPS latitude, longitude and time. 2. IPX7 waterproof rating (water depth of 1m, lasting 30 minutes). Speaker vibration reduction function, weather channel alarm function. Support Dual Tri‑watch function, easy to operate icons, menu system. 3. Support normal scan and priority scan. You can query the DSC call reception and transmission records. Standard NMEA interface (for RS‑422 protocol). Full dot matrix display. 4. Channel number display digits are optional, 3 digits (01B) 4 digits (2001). Built‑in GNSS module, support based for GPS, GLONAS, SBAS atellite. 5. Enhanced system (for WAAS / EGNOS / MSAS / GAGAN) (only for RS‑509MG) simple combination of arrow keys and programmable soft keys, smooth operation. 6. Support the latest Manine channel standard and DSC protocol standard. Supports DSC distress calls in 11 categories and all DSC calls in 3 safety categories. Specification: Item Type: VHF Marine Transceiver Material: ABS Frequency Range: TX: 156.000- 162 000MHz RX: 156.000- -163.425MHz Output Power: 25W Modulation Method: 16K0G3E (FM) , 16K0G2B (DSC) Frequency Stability: +/-5PPM Working Voltage: DC13.8V (t 15%) Channel Spacing: 25kHz Operating Temperature Range: -20-60℃ Antenna Impedance: 50Ω Output Impedance: 4ΩSize: Approx. 155x68x86mm/6.1x2.7x3.4in . Package List: 1 x VHF Marine Transceiver1 x Installation Base Bracket2 x Fixed Knob1 x Power Supply Wiring1 x 2-Way Hanging Buckle4 x Mounting Screw4 x Gasket1 x Manual