I had my installation yesterday and called later in the evening to see about ordering an AM21 for my HR24. I was told I couldn't get one because I had locals (SD not HD). That didn't make a whole lot of sense to me so I called again today and had another CSR tell me they weren't in their inventory anymore. He said he checked with a supervisor who confirmed it. I'm thinking they need to tell their web people because it's still advertised on their site. I see they are for sale on other sites but for a higher price.