Blasting Cone Sign - Danger Blasting Attach blasting signs to your traffic cones for greater impact.Specify blasting status with blasting cone signs. Simply attach non-reflective blasting sign on top of any traffic cone (sold separately). One-sided sign measures 10-1/2h x 12-3/4w. Weather and fade- resistant for long life. Plastic blasting cone sign reads DANGER BLASTING.