Product review (1 stars): Poor Dimensional Stability negates sealing
When received, this part worked fairly well. But, after a few months use the part has experienced "dimensional instability" and has shrunk a bit. As a retired rubber and plastic engineer, it is clear that the part has taken a "set" at the reduced dimensions and will never again "seal itself to dis-allow water passage."  This is a direct result of the composition (compound) used in molding the part, possibly combined with mold size and shrinkage after removal from mold.