A clamp comprising a spanner extending across a gap between first and second longitudinally extending edges of a band clamped onto a fluid conduit having a circumference orientated about an axis; a connecting assembly configured to tighten the spanner and band to the conduit and a gasket between the band and spanner and the conduit; the gasket comprising a first circumferential seal bead protruding from an inner side of the gasket and having a circumferential length that is equal to or greater than the circumference of the conduit and at least one standalone header bead protruding from the inner side of the gasket and disposed at least partially between the spanner and the conduit and having a circumferential length that is substantially less than the circumference of the conduit.