I just checked that for you and it seems that amigascne.org (the ftp the file download is from) have forgotten to include the file extension on that download. It is actually a DMS file (the Amiga Disk Masher format). Just add .dms to the end of the file name. The Windows emulator WinUAE handles DMS files just the same as a disk image (ADF). Not sure about Mac emulators but I would think UAE-X would be able to also open them in the same way, loading them into the emulator as a disk in DF0: Hope that helps.
You're welcome. Can't forget the main site!Harrison, thanks for the links, I sometimes forget that there's the main classicamiga web site!