Road Surface.5" (12.70mm) .59" (15.00mm) .67" (17.00mm) Mechanical Resistance 60 Tons 20 Tons 18 Tons i-STUD Technology LED Type Standard Standard Standard Operating Mode Flashing or Always ON Flashing or Always ON Flashing or Always ON Material Polycarbonate Aluminum* and Polycarbonate Aluminum* and Polycarbonate Power Supply Capacitor or