For those that are already certified CHT’s/CHRN’s this test would serve as a great Tune up. For those that have not yet taken the exams this would be a great place to start. You have 4 minutes for each question x 40 questions. This test has a little bit of everything, NFPA, Diving, Physiology, TCOMs, diving and hyperbaric terminology. Passing grade is 80%. GOODLUCK AND ENJOY THE TEST!!!