portion 38 is coupled to the living hinge 62 such as a v shaped gap 64 along the outer peripheral surface of the insert in particular embodiments the insert 34 can be a unitary piece of material that is molded cast machined or otherwise formed to have a central portion 38 and a raised peripheral portion 40 having a thickness greater than the central portion the peripheral portion 40 or at least the portion that will form the deflectable portion 42 is formed such that it is slightly larger than the opening defined by the corresponding section 56 of the inner peripheral surface the gap 64 can then be formed in the outer peripheral surface of the insert to form the deflectable portion 42 and the hinge 62 the outer peripheral edge 66 of the central portion can be formed or trimmed if needed so that it can fit within the cavity without contacting the inner peripheral surface in the illustrated embodiment the gap 64 is not formed in the portion of the insert 34 that extends into the lower cavity portion 48 thus the lower peripheral portion 40 of the insert that extends into the lower cavity portion 48 is simply defined by a raised portion of the insert however in other embodiments the entire extent of the peripheral portion 40 can be a deflectable portion 42 i e the hinge 62 can extend completely around the outer peripheral.