The Diploma qualification is designed specifically for those who want to progress their career in health and safety to a level of manager, director or head of health and safety.
the course content involves 3 units, with the exams held on line, open book with 6 weeks to complete for unit 1 and 4 weeks each for units 2 and 3
exams are held every 3 months
the following link will provide you with information on the course syllabus
https://www.nebosh.org.uk/qualifications/national-diploma-for-safety-and health-management-professionals/