A bullnose gas regulator is one with a screw-on fitting, usually called a POL connector. It is also often referred to as a male connection. POL is an acronym for the Prest O-Lite Company, which designed it. The connector has a left-hand thread, so you have to turn the nut anti-clockwise to tighten it.
Bullnose connectors come with either a handwheel, which you turn using only your fingers when attaching the regulator, or a nut, which you tighten with a gas spanner.
This type of regulator is a low pressure one. It can only be used with propane cylinders and delivers the gas at a pre-set pressure of either 28mbar or 37mbar.
The regulator is attached to the cylinder by screwing the connecting thread anti-clockwise into the valve outlet, and is considered an easy type to fit and use.
