From their disclaimer:
Operating this motorized bicycle or bicycle engine kit involves some risk of bodily injury…We are not responsible for injuries and/or damages resulting from operating this motorized bicycle or bicycle engine kit…Obey all traffic regulations. Always wear a helmet while riding. Remember that you are riding a motorized bicycle and other traffic may not be able to see you. Never operate your motorized bicycle on a pedestrian through way or sidewalk while the engine is running.
In the event of apocalypse…all disclaimer advice is irrelevant.