I started selling Nelson O2 systems in 1991 for hang gliding. Patrick McLaughlin of Mountain High asked if he could sell them also, and I told Jerry Nelson I didn't have a problem with it at all. Safety is safety, and the more sources for the equipment, the better. Mountain High eventually bought the Nelson line of regulators and flowmeters, and went on to develop and patent the Electronic Demand System (EDS) with altitude compensated pulse delivery. To me, it is the single greatest advance in oxygen delivery systems. I have used one in hang gliders and now sailplanes ever since they became available, and have been a dealer since the 90's. Now, at age 67, I set the delivery altitude at 5,000 ft. so I am on O2 even on takeoff. (Moriarty field elevation is 6,200 MSL.) As they say, "Don't leave home without it!"