RS bonded gaskets create a seal with DIN 3852, Type A (RS) parallel threads. Gasket outer rings are available in both 316 stainless steel and zinc plated carbon steel. The inner ring, bonded to the outer ring, consists of either Buna-N or fluorocarbon FKM. To order, specify pipe size, outer ring, and inner ring material. Note: For use only with Gyrolok RS fittings