Automatic Pen by British Roberson and Co, Dip pens for calligraphy and other types of technical drawing.
These high quality pens are made by hand in England and consist of two stainless steel nickel blades on a body of stain-resistant plastic. Developed for use with water-soluble ink, but works with most colors as long as they are mixed into a milky consistency.
No 3 has a nib size of 4.76mm.
Automatic Pens is available in 8 different sizes, 1.58mm - 25.4mm.