WATERMAN 18S SAFETY PEN BOTTOM UNIT WITH SPIRAL

THIS IS A WATERMAN 18S SAFETY PEN BOTTOM UNIT COMPLETE WITH SPIRAL .  THIS IS FOR THE LARGEST REGULARLY LISTED WATERMAN SAFETY PEN MADE.  OFTEN REFERRED TO AS THE WATERMAN "GIANT" SAFETY ALTHOUGH WATERMAN DID MAKE A LARGER #20 THAT IS EXCEEDINGLY RARE.  THIS BOTTOM UNIT IS NUMBERED FOR THE 18 BUT SHOULD WORK IN THE 48 ALSO.  UNIT APPEARS TO HAVE A GOOD TIGHT GASKET AND IS IN EXCELLENT CONDITION.  A VERY RARE WATERMAN PART.