It's a 23C series II. I have a fresh lens on the way for it now, a Nikon 50mm f2.8. The Nikon is supposed to be quite nice and will suffice for learning the ropes with this enlarger, but I predict an apo lens from Rodenstock or Schneider will come my way. We'll see how the Nikon does first, but I've invested in good quality lenses for the camera so it doesn't make sense to have lesser quality on the enlarger.