Abstract: Gasket material which is curved in cross-sectional shape. The curved section is placed between mating flanges situated around an opening such as an RF conduit. The radius of curvature is such that the modulus of elasticity is not exceeded upon compression of the flanges and thus the gasket is reusable while providing maximum contact pressure on the mating surfaces for sealing purposes. The curved contact area is offset from any openings in the flange for the passage of fastening means that provide the compressive action. This offset of the maximum pressure contact areas from openings increases the sealing capability of the gasket.