Warning safety signs come from a yellow background, black border and black symbol inside the panel, all of which have uniform shapes worldwide. Grounding warning sign is offered by Imentraffic with high quality and durable material. This product can be ordered in three types of reflective, colorful and luminous, as well as this sign can be used on three types of panel: Plastic sheet, galvanized sheet and electrostatic frame; each has its own special advantages.