Amazon.com: High Gain Long Range Magnetic Base Replacement Antenna Compatible with Garmin GPS Alpha 100 200 200i Astro 220 320 430, Eifagur : Electronics
Garmin Yellow Flexible 15" long range antenna for Astro 220 320 430, Alpha 100 | eBay
Garmin Astro 320 vs Garmin Astro 430
Garmin Astro 220 / 320 Flexible 18" Antenna & DC 30 Tuff Skin Antenna Set | eBay
Muti-Color Long Range 36cm FP-71 SMA-Male Flexible Antenna for Handheld GPS Garmin Astro 220 320 430 900 Alpha 50 Alpha 100 - AliExpress