Unidirectional Solar Road Stud Light Supplier In UK-RUICHEN . Rennicks UK Solar Active Road Stud SR21 Unidirectional or bidirectional road stud with LED illumination & reflector White - NSPL500DS (2500k-2800k) Red - C503B-RAN Amber - C503B-AAN Green - NEPE510JS prEN 1463-3 pti (Draft) 100 Hz minimum, with