Must wear a safety helmet, which of the safety signs is included?

Command flag. The national standard "Safety Signs and Guidelines for their Use" (GB2894-2008) stipulates signs that convey safety information and the principles for their installation and use. Among them, there are 16 directive signs: Must wear protective glasses, must wear blackout goggles, must wear dust mask, must wear gas mask, must wear ear protectors, must wear safety helmet, must wear protective cap, must wear Seat belt, must wear life jacket, must wear protective clothing, must wear protective gloves, must wear protective shoes, must wash hands, must be locked, must be grounded, must be unplugged. Instruction signs are graphic signs that force people to take certain actions or take precautions. The geometric shape of the instruction sign is a circle, with a blue background and a white graphic symbol.