To be honest its not very good..... its mostly how to wash your gear....... most of the ins and outs of regs and stuff are kept pretty well guarded. If you want to know about equipment send me a PM. Im PSI cert to inspect tanks and valves and do O2 cleaning. I dont do regs but have a very indepth general knowledge of the inner workings. Bcds are really simple and i can walk you through them in 5 min.... i just got all my certs in august so its still pretty fresh.