Statotherm R profile rings R901/B are made from permanently elastic, expanded graphite (purity ≥ 99.85%, ash content ≤0.15 %, chloride content ≤20 ppm) without binders or fillers. Statotherm R profile rings R901/B are almost maintenance-free and are intended for exposure to extreme temperature cycling and/ or high or low temperature ranges which cannot be withstood by elastomeric O-rings.