ECO-54 road embedded solar studs (bidirectional beaconing, 3 constant white LED per side). SR-i21 | NOKIN solar road stud light NOKIN solar road stud light is a Portuguese technologic solutions company, based in Braga, which manufactures and supplies a wide range of products, services and a high quality solutions in the areas of Road Safety, LED Lighting, Electronics Displays and Fiber Optics.