Zeiss Kodak Anastigmat f/6.3 No. 4 by Bausch & Lomb, in great condition for its age.  Glass has minor cleaning marks on front and rear elements but is otherwise clean and clear.  Shutter casing is drilled for an external mechanical release, but this does not impede usability.  License-built Compound shutter is accurate through its range of speeds and runs silently for maximum stealth!  Covers 4x5".  No. 0 mount, with retaining ring.