(1) The employer shall have 5 working days from receipt of the petition in which to file a counter petition with the board.

(2) The employer shall file a counter petition when the employer disagrees with the appropriateness of the proposed unit as described in the petition.

(3) The petition shall contain:

(a) the specifics of the nature of employer's disagreement with the petitioner's proposed appropriate unit;

(b) a detailed description of the employer's proposed appropriate unit;

(c) the number of employees in the employer's proposed unit;

(d) the expiration dates and brief description of any contracts covering any employees in the employer's proposed unit; and

(e) any other relevant facts.

(4) The employer shall serve a copy of the counter petition upon the petitioner.