Md. Code, Transportation § 22–401.1

A vehicle from which ice cream products and similar products are sold may be equipped with, and the driver of the vehicle may use, a bell not exceeding 3 1/2 inches in diameter, or a set of bells, provided that no bell or set of bells may be:

(1) Operated by mechanical or electrical means or by any means other than manually;

(2) Amplified by any electrical or electronic means;

(3) Capable of emitting sound audible under normal conditions from a distance of more than 400 feet;

(4) Used for any purpose between the hours of 10 o’clock p.m. and 8 o’clock a.m.; or

(5) Used as an ordinary warning signal at any time.