Hi, I'll answer this. The m-1000 B is the same as the m-1000 with a few miner differences. 1. The B has a place where you can hook up an external antenna. 2. the B feels different then the 1000 it has grooves running length wize along all 4 sides. as far as performance, the two receivers are identical. Chris On Thu, 3 Jan 2008 14:35:31 -0600, "Howard Kaufman" <wa9top@xxxxxxxxx> wrote: > I just got my new m1000 in the mail, I see m1000 and m1000B >stuff on the mini disk. What is the difference and which did I get? > Chris Grabowski - Customer Support and Product testing Phone: 888-757-6810 EXT. 113 Email: chris@xxxxxxxxxxxxxxxx