This is extremely small O-ring which is used for the ultra precision machine. The available mold size we have is from minimum thickness of 0.3 and minimum inner diameter of 0.5.

 We have round shape string for temporary use in stock. It can be used as an O-ring by adjusting the length and gluing both ends.
Thicknes of stock item φ: 2/2.5/3/3.5/4/5/5/7/6/7/8/8.4/9/10
Material type in stock: NBR/FKM/VMQ (other size or material can be ordered.)