Seems to fit most of my 4 inch fittings but with the tapered shape only a very small ring actually makes contact with the edge of the outer rim of the hose. different fit. It seems to fit quite snugly if you squeeze them together hard enough. Time will tell how the quality of the connection will hold up. Still needs a hose clamp to even hold the hose to this fitting. Kind of defeats the purpose of a threaded fitting. To be honest I've only bought one type of hose from PSI. So your mileage may differ from other brands of flex hose.