I've purchased many WS 210mm F6.7 and WS 250mm F6.7 lenses, as well as a couple of 180mm WS lenses, all of which came in LS23 Seiko #2 shutters. BTW this is the same size shutter that's in RB67 lenses. I've also purchased Seiko #2 shutters from Japan, all were marked LS23.