Purchased to replace a third failed Hadley 850D for horns on my camper van. There is no comparison. The Hadley had an air cleaner about 5/8 inch in diameter and the crankcase end cap kept falling off. It had an efficient replaceable air filter, solid crankcase construction and, in addition, a built-in check valve. Duty cycle is 23% and 350°C is 100%. And it inflates the system 1/4 times faster and keeps the pressure for days thanks to the check valve. I'll be cutting off a tube soon so I can inflate the tires.