annular shoulder 24 of annular seal 12 the tool 500 as shown also includes threadedly adjustable top shoe 530 referring to fig5 the improved seal 50 of the present invention is shown integrally incorporated in a well cementing tool 500 as shown the seal 50 is formed as part of a first the outer cylindrical member 502 of the tool 500 alternately the seal 50 could be formed on the inner cylindrical member 504 of the tool 500 the seal 50 is similar in construction to the seal 20 having first frusto conical annular lip 16 39 and second frusto conical annular lip 18 39 extending from body portion 20 39 the first lip 16 39 and second lip 18 39 may be formed having annular ribs 26 39 on the interior thereof as shown the tool 500 includes threadedly adjustable top shoe 530 referring to drawing fig6 the improved seal 80 of the present invention is shown integrally incorporated along with annular elastomeric seal back up members 84 the seal 80 is similar in construction to the seal 50 having first frusto conical annular lip 16 34 and second frusto conical annular lip 18 34 extending from body portion 20 34 the first.