Abstract: A single piece seal that functions both as a seal and a spring. The single piece seal includes a central bore for receiving a communication line such as a wire or a fiber optic cable. The single piece seal also includes a first and second radial sealing ring, and at least a first axial compression portion between the first and second rings. Preferably the seal includes a second and third compression portions each extending from an outer edge of the first and second rings respectively. Each of the rings may have and radial thickness which is 25% or more greater than the radial thickness of the first axial compression portion, and each of the rings may have an axial length which is 50% or more of the axial length of the first axial compression portion. Preferably the second and third compression portions have an axial length which is at least twice that of either of the rings. Each end of the seal have tapered counter bores communicating with the central bore.