This is a Astro DC50 Replacement AC Adapter Wall Plug. The Garmin part number for this product is 010-10635-00
The Garmin Alpha 300 and Alpha 300i handhelds have been out for a few weeks now. Now that our staff has got more field time with it and we got to hear feedback from customers, we thought it would be a great time to make a breakdown of the difference between the Alpha 300 and Alpha 200 handhelds.