A highly visible emergency marker deployed behind a stationary vehicle to prevent rear collisions. It features bright red retroreflective borders and a weighted base to withstand wind buffeting from passing traffic. Many jurisdictions mandate carrying at least one in the trunk by law.
Heard on the job
Grab the warning triangle from the trunk and walk it back fifty paces before you start jacking up that flat tire.
Insider tip
Always place the triangle far enough behind the vehicle to give highway traffic time to react and change lanes.