Eclipse Q seals are unique in that they make use of elastomer contact on both the dynamic and static side of the gland. In this design, the PTFE element acts as a carrier for a rubber quad seal on the dynamic side and gets additional sealing energy from O-Ring(s) on the static side. The intent of the dual elastomer contact is to create a barrier capable of keeping two different media types from mixing. Piston accumulators often make us of this type of seal. Available in piston configurations.