Short thread screw seals ND9 are made of PP and are supplied with fitted septa made of a variety of materials. They have a 6 mm centre hole and are available in different colours. The screw caps are similar in shape to the crimp caps and are therefore also suitable for robotic handling.

Septa made of Viton have a very high resistance against a wide range of solvents. These septa are highly recommended for use with chlorinated solvents.
Viton septa are not suitable for multiple injections or high injection speeds.