Mo. Rev. Stat. § 307.207: Equipment required.

Every electric personal assistive mobility device (EPAMD) when in use on a roadway during the period from one-half hour after sunset to one-half hour before sunrise shall be equipped with the following:

(1) A front-facing lamp on the front or carried by the rider which shall emit a white light visible at night under normal atmospheric conditions on a straight, level, unlighted roadway at five hundred feet;

(2) A rear-facing red reflector, at least two square inches in reflective surface area, or a rear-facing red lamp, on the rear which shall be visible at night under normal atmospheric conditions on a straight, level, unlighted roadway when viewed by a vehicle driver under the lower beams of vehicle headlights at six hundred feet.