Maryland Code, Criminal Law § 4-305.1

(1) transport a rapid fire activator into the State; or

(2) manufacture, possess, sell, offer to sell, transfer, purchase, or receive a rapid fire activator.

(1) possessed the rapid fire activator before October 1, 2018;

(2) applied to the federal Bureau of Alcohol, Tobacco, Firearms and Explosives before October 1, 2018, for authorization to possess a rapid fire activator;

(3) received authorization to possess a rapid fire activator from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives before October 1, 2019; and

(4) is in compliance with all federal requirements for possession of a rapid fire activator.

(1) a police officer or other person employed by a law enforcement agency under circumstances in which the officer or other person possesses the part or parts in accordance with authorization given by the law enforcement agency; or

(2) a person who has registered a machine gun with the Secretary of State Police under § 4-403 of this title if the part or parts are possessed for use in only, and necessary for the proper function of, a machine gun that is currently registered by the person under § 4-403 of this title.