Be Seen. Be Safe. MDI has a range of high-visibility safety vests to make fire, rescue, police, emergency medical services personnel, towing and recovery personnel, and hazardous materials contractors very conspicuous while they’re on the job. The Red Vest and 5-Point Break-Away Red Vest, with their brilliant reflective bands, stand out in daylight or headlights. Most MDI Emergency Responder Vests are ANSI Class 2, ANSI Class 3 compliant and come in a durable mesh or solid polyester material.