MDZ Shield R&D Tumbleweed contractor located in West Los Angeles Hesperia California is hereby recognized as the first city in the nation to install MDZ Shields for child safety. 2 Foot Danger Zone Gap Dangerzone gaps approximately two feet, creating seating high for children preventing death or injury from side collision. MDZ Shield rear guard guaranteed for the life or the bus excluding collision or air failure. Snow or ice does not accumulate on shield. MDZ Shield receiver guaranteed for the life of the bus excluding collision or air failure.