This is a Wahl model 431D Check pattern silver filled fountain pen c1921-1924. It is the shortest, at 4 3/8 inches, of the three sizes of clip metal pens with the engine turned Check design, a repeating panel of checks in a line pattern on the cap and barrel. The pattern is called Unique in the 1921 catalog, and Check from 1922 onward. The barrel has a rectangular blank for engraving in one of the panels. It features a Number 3 14 karat gold nib stamped Wahl. Model 431 also came as a ringtop pen and a choice of silver filled for $6.00, 12 karat yellow gold fill or sterling silver for $6.50 or 14 karat green gold fill for $7.50. Matching Eversharp pencils were available for $1.50, $3.50, and $4.50, respectively.