(a) Any former member of the Georgia Class Nine Fire Department Pension Fund created by Chapter 7A of this title who becomes a member of this pension fund shall be entitled to receive creditable service for the time he or she was a member of such other pension fund as provided by this Code section. Upon request, the Board of Trustees of the Georgia Class Nine Fire Department Pension Fund shall transfer to the board of trustees of this pension fund the full amount of dues paid by such member while he or she was a member of such other pension fund.

(b) Any member receiving creditable service under this Code section shall receive creditable service in this pension fund equal to the number of years of his or her membership in the Georgia Class Nine Fire Department Pension Fund.

(c) Upon retirement, a member who receives creditable service under this Code section and who is otherwise eligible to receive a retirement benefit under this pension fund shall have a vested right in and to a monthly benefit payable for the member's lifetime equal the sum of:

(1) A pro rata amount of the maximum monthly retirement benefit in effect on the date of such termination of service, which amount shall be determined by the ratio of years of membership in this pension fund to 25 years; and

(2) A pro rata amount of the maximum monthly retirement benefit provided in Chapter 7A of this title in effect on the date of such termination of service, which amount shall be determined by the ratio of years of membership in such pension fund to 25 years.