The -### refers to the manufacturer, otherwise the same model numbers are all the same. If you find an unactivated one, contact the access department at Directv with the RID number to be sure it's not a previously leased unit. If it is, they won't allow you to activate it. There are some available on eBay, but those are the suspect ones. Directv may well give you one at no additional cost aside a new two year commitment. You will get the commitment regardless of where you get it if it's a leased unit. If you find an owned one there is no additional commitment on an existing account.