If, due to physical or mental illness, Executive shall be disabled so as to be unable to perform substantially all of his duties and responsibilities hereunder, which disability lasts for more than an uninterrupted period at least 180 days or a total of at least 240 days in any calendar year (as determined by the opinion of an independent physician selected by the Board(s) of Directors of the Employer), Employer, acting through its Board(s) of Directors, may designate another executive to act in his place without further liability under this Agreement except for those benefits offered Executive pursuant to any long-term disability plans of Employer.