N.J. Stat. § 39:3-54.18
The Director of the Division of Motor Vehicles shall prepare suitable identification cards bearing the signature of the director, which, upon the request of the mayor or chief executive officer of any municipality recognizing and being served by a volunteer fire company, on a form and in a manner prescribed by the director, shall be forwarded to the mayor or chief executive officer, to be countersigned and issued by the mayor or chief executive officer to the chief or first assistant chief of the volunteer fire company. Identification cards issued pursuant to this section shall be considered permits to display and operate red emergency warning lights, sirens, or both, as provided for in this act, and no lights or sirens shall be mounted prior to the issuance of the identification cards. Each chief or first assistant chief of a volunteer fire company shall carry the identification card while red emergency warning lights, sirens, or both, are displayed on his vehicle.
N.J.S. § 39:3-54.18