An annular seal comprising: an annular outer casing comprising a plurality of radially extending mount holes configured to receive a corresponding structure of a plurality of seal segments ; the plurality of seal segments , wherein: the plurality of seal segments is coupled to the annular outer casing to cumulatively form an annular sealing surface ; the annular sealing surface is configured to face a rotating structure to inhibit fluid leakage between the rotating structure and the annular sealing surface ; and each seal segment of the plurality of seal segments is configured for independent radial movement relative to other seal segments of the plurality of seal segments and comprises a trunnion configured to be received within a respective one of the plurality of radially extending mount holes ; and a plurality of spring components configured to bias the plurality of seal segments relative to the radial movement; characterised in that : the plurality of spring components comprises two spring components per seal segment of the plurality of seal segments , the two spring components comprise a forward spring component and an aft spring component , and the forward spring component and the aft spring component are coupled to a flange of the annular outer casing and to a radially outer surface of each seal segment of the plurality of seal segments . an annular outer casing comprising a plurality of radially extending mount holes configured to receive a corresponding structure of a plurality of seal segments ; the plurality of seal segments , wherein: the plurality of seal segments is coupled to the annular outer casing to cumulatively form an annular sealing surface ; the annular sealing surface is configured to face a rotating structure to inhibit fluid leakage between the rotating structure and the annular sealing surface ; and each seal segment of the plurality of seal segments is configured for independent radial movement relative to other seal segments of the plurality of seal segments and comprises a trunnion configured to be received within a respective one of the plurality of radially extending mount holes ; and the plurality of seal segments is coupled to the annular outer casing to cumulatively form an annular sealing surface ; the annular sealing surface is configured to face a rotating structure to inhibit fluid leakage between the rotating structure and the annular sealing surface ; and each seal segment of the plurality of seal segments is configured for independent radial movement relative to other seal segments of the plurality of seal segments and comprises a trunnion configured to be received within a respective one of the plurality of radially extending mount holes ; and a plurality of spring components configured to bias the plurality of seal segments relative to the radial movement; characterised in that : the plurality of spring components comprises two spring components per seal segment of the plurality of seal segments , the two spring components comprise a forward spring component and an aft spring component , and the forward spring component and the aft spring component are coupled to a flange of the annular outer casing and to a radially outer surface of each seal segment of the plurality of seal segments . <EOS>