Garmin GXM 31 Smart Antenna for GPSMAP 430/430s and 440/440s Chartplotters XM data antenna delivers location-specific, animated, high-resolution weather data in chart-overlay form Covers the continental U.S. and 100 miles into U.S. coastal waters Compatible with Garmin GPSMAP 430/430s or 440/440s chartplotters; requires subscription Includes a 30-foot connecting cable with a Positive Lock, waterproof Mini USB connector Weighs 2 pounds and measures 2 inches in diameter and 2 inches in depth