Policemen or firemen employed by a political subdivision of the Commonwealth or by the Commonwealth shall, through labor organizations or other representatives designated by fifty percent or more of such policemen or firemen, have the right to bargain collectively with their public employers concerning the terms and conditions of their employment, including compensation, hours, working conditions, retirement, pensions and other benefits, and shall have the right to an adjustment or settlement of their grievances or disputes in accordance with the terms of this act.