Crimp and headspace seals ND20 are made of aluminium and are supplied with fitted septa made of a variety of materials. There are the following different types of caps available:

Plain caps with a 10 mm center hole. These caps are suitable for standard applications. They are available in several colours on request.

Clear lacquered caps, so called headspace caps, with a special score line that breaks when the internal pressure reaches 3.0 ± 0.5 bar. The excess pressure is then released, and the risk of the vial exploding can be avoided.

Clear lacquered centre tear-off caps and complete tear-off caps. These caps are available in several colours on request.

Gold lacquered, magnetic crimp caps with 5 mm centre hole to be used with CE HS500/HS800, CTC 500, as well as Fisons HS500 / HS800 instruments.

Gold lacquered, magnetic crimp caps with 8 mm centre hole to be used with CTC Combi PAL instruments.

Red lacquered, magnetic bimetal crimp caps with 8 mm centre hole to be used with CTC Combi PAL instruments.

These septa, made of silicone blue transparent / PTFE white, are temperature-resistant from -60 °C to 200 °C. They are 3.0 mm thick and have a hardness of 45° shore A. They have better purity than septa made of natural rubber or red rubber. However they have less effective resealability properties and are therefore more suitable for single-injection applications.

Due to their high cleanliness, they are especially used for critical and sensitive analysis.