Representatives selected by public employes in a unit appropriate for collective bargaining purposes shall be the exclusive representative of all the employes in such unit to bargain on wages, hours, terms and conditions of employment: Provided, That any individual employe or a group of employes shall have the right at any time to present grievances to their employer and to have them adjusted without the intervention of the bargaining representative as long as the adjustment is not inconsistent with the terms of a collective bargaining contract then in effect: And, provided further, That the bargaining representative has been given an opportunity to be present at such adjustment.
43 P.S. § 1101.606