LED flash rate To be of the size and type shown on the drawing marked with the Department's 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 each flash