For sale is a LOT OF 100,3M YELLOW ONE WAY SAFETY ROAD MARKERS REFLECTORS RPM-190-Y. I tested one of them, heated the glue with a heat gun, put it on concrete and stepped on it. The marker held VICIOUSLY and now I cannot pull it off the concrete. I drove my forklift over it and it does not care. Mark your yard, driveway, patio, or put it on your rose petals, you will be very happy.