This is a Conklin Endura medium size pen in Pearl & Black celluloid c. 1930. Note the typical discoloration, more prominent in the barrel. The 1929 model 47PBC had only one cap band, and by 1931, Conklin was adding a gold filled Crescent inlay above the clip of the now two cap band pen, so this 4 7/8 inch long 47PBC is in between, with two cap bands and no Crescent. It sold for $6.00 and the matching pencil sold for $4.00. The 14 karat gold Conklin Endura nib is not hallmarked.