I am still figuring out whether A.R.S. and A.R.S. Amoretto are machines from different or the same manufacturer.
However, ARS Amoretto and ARS Knitter are the same machines; these model names are used interchangeably.
A.R.S. Automatic Home Knitter
A.R.S. Knitter M
A.R.S. Knitter MT
A.R.S. Amoretto M-2
A.R.S. Amoretto MT-4
A.R.S. Knitter SM-18