Amazon.com: High Gain Long Range Magnetic Base Replacement Antenna Compatible with Garmin GPS Alpha 100 200 200i Astro 220 320 430, Eifagur : Electronics
20 pc Garmin GPS Long Range 47" Orange Antenna Alpha 100 and Astro 220 320 430 | eBay
Flexible 16 " Long Range Antenna Garmin Astro 220/320 - Alpha 100 GPS | eBay
Garmin Astro Long Range Antenna
Garmin Astro 220 GPS-based Dog Tracking System - DC 20 Only - KnifeCenter - GM0101080500 - Discontinued