The Noodler’s Ink colored piston filler set includes: black, red/orange, turquoise, burgundy, and navy blue (additional colors will be available as time passes). They are a classic 1960s design (note the classic bow windowed ink chamber) made from a celluloid derivative developed by a company in Rochester, New York – that has several trade names (including some high priced variants, such as “vegetal resin”). The piston seal is also made of the same material used in most high end piston filling pens of today (a type of nylon). The nib is stainless steel tipped with a hard platinum group metal alloy. The feed is classic as well – being hand made of hard rubber (also known as “ebonite”) and unique from plastic feeds in that it can be gently heat set to many different pen nibs without any loss of capillary abilities. The nib size is the classic #2 – the most common nib size of the past 100+ years….and thus the pen can be fitted with a larger number of nibs than any other size. The edge of the cap and section are banded for long term stability and the cap has no internal restrictions (so that a wide shouldered 1940s nib as well as a narrower 1930s nib can fit if the owner chooses to do so).