Creates a positive seal. Controlled swelling gasket. Thickness will not decrease. Eliminates re-torque of valves. High-tensile strength. Handles ex flange pressure and forms a leak proof seal. Black latex coating. Product Features:Creates a positive sealControlled swelling gasketThickness will not decreaseEliminates re-torque of valvesHigh-tensile strengthHandles ex flange pressureForms leak proof sealBlack latex coating