Abstract: A seal is disclosed for installation on a port of a medical device which preferably is a trocar. A seal in accordance with present invention has a first portion which has a bore and a first outer wall of a first thickness. The base of the first portion engages the port. A seal in accordance with the present invention has a second portion with a top and a passage through the top. The second portion has a second outer wall which is integral with the first outer wall and that has a thickness at its juncture with the first outer wall that is less than the thickness of the first outer wall.

Abstract: A seal is disclosed for installation on the proximal end of a trocar. The seal is generally cylindrical in shape and has an upper portion and a lower portion. The lower portion is formed for mating engagement with the proximal end of the trocar. The upper portion comprises a central hole for insertion of a surgical instrument and a plurality of folds in proximity to the central hole. The folds allow the central hole to dilate and contract to seal on surgical instruments of varying diameters, and various configurations of folds are disclosed.