Ed-Rings, also known as fitting seals or DIN 3869 profile sealing rings, are fluid connector seals for hydraulic fluid power systems in accordance with DIN 3869. Ed-Rings are molded elastomeric rings used as axial static soft seals in combination with threaded elements, such as threaded ports, stud ends, tube connections and fittings. The trapezoidal cross-section gives the Ed-Ring the advantage of protecting the fluid connector seal from twisting in the groove and reducing the deformation of the seal when used under high pressure. DIN 3869 fluid connector seals cover a size range from an inner diameter of 6,5 mm (M8x1 thread) to a diameter of 56,5 mm (M60x2 – G2” thread). They are commonly supplied in NBR for use with mineral oils and greases, FPM/FKM (Viton) for temperatures up to 200 °C and optionally EPDM for media such as hot water and steam.