Bay II. Fits Rolleiflex 3.5F and others. Doesn't fit Rolleicord (Bay I) or my 2.8D (Bay III). Excellent condition, glass looks great, as does the metal ring. Genuine Rollei leather case is excellent, even has the little band across the back for mounting on your strap.
$25 + $3 domestic shipping (US), paypal works (or check, M.O.)
A couple of pics, those are reflections in the filter glass, not defects.