I have an old (but very good) Weber barbeque that uses the quick disconnect fittings. These convert a standard propane cylinder to a quick disconnect. The plastic insert that you use to screw it on is made to break off when the torque is correct, and the remaining piece is easy to remove. It works great and there are no propane leaks. I have used three of these over the years and they have lasted the full lifetime of the tanks they were installed on.