Unidirectional Solar Road Stud For Sale NOKIN Bluetooth synchronized solar road stud NK-RS-A6-1 specification: Material is Aluminium (GB-ADC-12)+PC (Japan Brand). Lens is PMMA (ASTM D4280 & EN1463-1 standard). Power supply of this solar road stud is USA Brand High Efficient Solar Panel 5V/60MA. Battery is Lithum battery (3.2V/500mah).