It’s an older (2005-ish?) Sigma 17-70mm f/2.8-4.5 DC Macro. No IS and focus isn’t earth-shatteringly fast, but the landscape doesn’t move too quick, either. Nothing special by today’s standards and Sigma has released an updated version (or two?) of it in the intervening years. It’s designed for APS-C cameras, but they claim the advertised focal length is a full-frame number. I asked once about that and that’s the answer I got. Not sure why that is, but whatever. The pictures are what they are. LOL
I’ve actually toyed about with the idea of replacing it with a used later-release Canon 24-70mm f/4L. I rarely use the wider ends of focal length nor aperture anymore. There’s quite a bit of vignetting wide(r) open and past about 60mm it softens a bit. But then again I usually add vignettes anyway.
Thanks.