This is a Wahl Wave Design silver filled large clip fountain pen c. 1925-1926. The Wave Design, introduced on pencils in 1924, is a panel of straight lines with a small curve out grouped evenly that create a series of waves repeating around the cap and barrel. Offered on pens from 1925 to 1926. This 4 15/16 inch long pen is the largest catalog size clip Wahl pen, model 645D and normally comes a with a 14 karat gold Number 4 size nib stamped WAHL 4 14 K. This example has a larger Number 5 nib. The barrel has a rectangular blank for engraving, opposite the lever. The pen sold for $5.00 and the matching model 35 Eversharp pencil sold for $2.00.