I picked this up a few years ago on sale at my barber which also carries some off-the-beaten-path fashion brands and grooming items. The maker is Naketano. I don’t know much about them other than it appears to be a German brand and many of their pullovers feature chunky nautical rope pulls like the ones here.
That said, I really do like the multi-layered turtleneck and that the fit is slim, the weave is soft, and it is casual yet polished. I generally get positive comments when I wear this one.