The Autofiller version of the twist filling fountain pen is simplistic. An ornate stick is mounted to the inside of a standard sac through a hole in the end. The stick is accessed under a blind cap and can freely rotate. There is a more elegant version with the stick emerging from a narrow hole (the first pen pictured), and a cruder version where the end of the barrel screws off revealing a barrel sized hole (pictured second). It is easy to see why the little stick for twisting is more easily lost from pens with the second type of blind cap.