A compressor comprising: a housing ; a shaft rotatably mounted with respect to the housing ; a compressor bundle arranged around the shaft and disposed at least partially within the housing ; and an annular seal , comprising: an inner radial surface defining an inner diameter of the annular seal ; an outer radial surface opposing the inner radial surface and defining an outer diameter of the annular seal , the outer radial surface forming an outer sealing surface , wherein the annular seal is mounted about a portion of the compressor bundle , such that the annular seal is disposed between the housing and the compressor bundle , characterized in that the outer radial surface further defines at least one annular groove and a plurality of slots spaced circumferentially about the outer radial surface , each slot having an end terminating in the at least one annular groove ; the annular seal further comprising a first axial sidewall forming a sidewall sealing surface and a recessed portion ; and a second axial sidewall opposing the first axial sidewall, wherein the annular seal forms a generally rectangular cross-section; wherein the at least one annular groove and the plurality of slots are configured to maintain a low pressure environment across at least a portion of the outer radial surface ; and wherein the second axial sidewall , the recessed portion , and the inner radial surface are configured to maintain a high pressure environment there across during the operation of the compressor . a housing ; a shaft rotatably mounted with respect to the housing ; a compressor bundle arranged around the shaft and disposed at least partially within the housing ; and an annular seal , comprising: an inner radial surface defining an inner diameter of the annular seal ; an outer radial surface opposing the inner radial surface and defining an outer diameter of the annular seal , the outer radial surface forming an outer sealing surface , wherein the annular seal is mounted about a portion of the compressor bundle , such that the annular seal is disposed between the housing and the compressor bundle , characterized in that the outer radial surface further defines at least one annular groove and a plurality of slots spaced circumferentially about the outer radial surface , each slot having an end terminating in the at least one annular groove ; the annular seal further comprising a first axial sidewall forming a sidewall sealing surface and a recessed portion ; and a second axial sidewall opposing the first axial sidewall, an inner radial surface defining an inner diameter of the annular seal ; an outer radial surface opposing the inner radial surface and defining an outer diameter of the annular seal , the outer radial surface forming an outer sealing surface , wherein the annular seal is mounted about a portion of the compressor bundle , such that the annular seal is disposed between the housing and the compressor bundle , characterized in that the outer radial surface further defines at least one annular groove and a plurality of slots spaced circumferentially about the outer radial surface , each slot having an end terminating in the at least one annular groove ; the annular seal further comprising a first axial sidewall forming a sidewall sealing surface and a recessed portion ; and a second axial sidewall opposing the first axial sidewall, wherein the annular seal forms a generally rectangular cross-section; wherein the at least one annular groove and the plurality of slots are configured to maintain a low pressure environment across at least a portion of the outer radial surface ; and wherein the second axial sidewall , the recessed portion , and the inner radial surface are configured to maintain a high pressure environment there across during the operation of the compressor . <EOS>