Md. Code, Transportation § 21–805.1

(a) A person may not drive a vehicle that is designed with a maximum speed of more than 25 miles per hour and less than 55 miles per hour on a highway unless the vehicle properly displays a limited speed vehicle emblem in accordance with this section.

(b) A limited speed vehicle emblem required under this section shall be:

(1) A truncated equilateral triangle that is at least 14 inches high with a red reflective border that is at least 1.75 inches wide and with a fluorescent green center; and

(2) Permanently affixed to the rear of the vehicle, with the base down and at a height of between 3 feet and 5 feet above the ground.