Incompressible-can be deformed, depending on durometer and cross section, but can never be reduced in volume
Extensible-can be assembled over a projection or shoulder and snap tightly within a groove
Highly impermeable-can serve as a tight barrier against the passage of gases or liquids
Elastic-little flange pressure required to effect intimate contact with gasket, allowing it to move with the flange surfaces, always maintaining a seal
Complies with RMA (Rubber Manufacturing Association)