ChemBria septa are available in three different materials: soft natural rubber, white rubber, and silicone. The shape of the septa is optimized for NS glass joints, providing a perfect seal ideal for reactions under inert atmospheres or reactions involving gases. Our septa come in the four most common glass joint sizes, and all are produced at the same factory, ensuring consistently high quality and full traceability. ChemBria septa meet the highest standards, with material quality independently tested by accredited laboratories.