BSR is Bernina Stitch Regulator. I have had two Berninas - the older 820, which I had for about 25 years. Just traded it in for a new 820. I'm still getting used to the new one. Also have a Brother from Wal*Mart, which I carry around because it's only about 10#. When I was checking, I had it down to a Janome and a Bernina. Because I had my first Bernina for so long, I went with it even though it was more pricey.