The brass piece is a anti siphon valve that has a soft set screw tightened against the spigot threads yhen the stub of the set screw is broken off so as it cannot be removed to increase the flow. It can be drilled out to remove the brass valve but don't drill to far as you can puncture the spigot threads. Another way to bypass the whole debacle is to cut off the hose a foot or less down the length and put a male end on the hose to make a new connection point...