#16 - Red and Black Mottled Hard Rubber - These are the earlier slip cap eye dropper pens. Both have #6 size nibs but you can see the difference in the diameter of the pens. The top pen is an earlier model. The markings in these pens vary. Some like the bottom pen is mainly black and others are primarily red.

#52 - Black Chased Hard Rubber - These pens come with a number of different types of bands and overlays. They are found with and without pocket clips. They are available in red hard rubber as well as red and black rubber models. These are the most common of the full size rubber pens.

#52 1/2 - Red and Black Mottled Hard Rubber - The 1/2 on the end of the number notes that the pen is a smaller diameter than a standard 52. They are available in the standard colors and trims as the other pens of the time.

#94 Olive Ripple - 1928-1930 - This is one of the later hard rubber pens that Waterman made. The colors are unusual and include blue green ripple, rose ripple, and red ripple. There is a smaller model 52V that is found in the same colors as well as. matching pencils and desk pens. The Olive Ripple pens and pencils must have been the first made and Waterman was trying a new numbering system. This pen is marked #994 and the matching pencil is #995. These numbers are later dropped to a simple 94 and 95. All of the other colors are just marked 94 or 95.