Code of Alabama
Division 2 - Lights, Lamps and Reflective Devices.
Section 32-5-246 - Reflective Devices for Slow-Moving Vehicles - Required; Design.

When operated, propelled, driven, towed, pushed, or otherwise moving over, along, or across any highway in this state, every vehicle which has a maximum potential speed of 25 miles an hour, implement of husbandry, farm tractor, or special mobile equipment shall be identified with a reflective device as follows:
(1) An equilateral triangle in shape at least 16 inches wide at the base and at least 14 inches in height, with a bright red border, at least one and three-quarter inches wide of highly reflective beaded material;
(2) A center triangle, at least 12 1/4 inches on each side of yellow-orange fluorescent material.