This is a Conklin Nozac model C-59 7M Word Gauge Jet Black piston filler c. 1936. This 5 1/8 inch long model is an interesting combination of a ten faceted cap and lower barrel and a rounded clear ink view upper barrel. The two barrel pieces are threaded and sealed together. The C-59 Nozac was also available in marbled Red Pearl and Green Pearl and sold for $7.50. The markings on the ink view window indicated how many thousands of words of ink was left in the pen. Conklin was transitioning to the new 14 karat gold Cushon Point nibs in 1936. Catalog images show this pen with the Conklin platinum plated circle stamped nib. The pen has the earlier 1918 patent clip, which Conklin replaced with a new patented clip in 1936. The inlaid crescent appears below the pocket clip, moved from above the clip by 1933. Nib grades offered were extra fine, fine, medium, coarse, stub medium, stub broad, left oblique, two way and Recorder in extra fine, fine and medium.