This valve contains a built in excess flow safety valve, this is designed to stop the gas flow in case of a cut or large leak in the pipe further down the gas line. This prevents gas flowing through when not connected to an appliance, i.e if you were to connect this to your gas bottle, then open the bottle, gas would NOT flow through as nothing is attached further down the line. Once connected to the regulator and the gas appliance the display dial must then be pressed inwards to allow gas to flow as it has a push/pull button function that controls the flow valve.

This gauge is for use with POL type LPG gas cylinders only 
The gauge fits between the bottle valve and regulator 
Once in place it will give a reading of current gas level
This valve has a built in one way flow valve
The gauge can also be used for leak testing to indicate a possible leak (drop in pressure) further down the line or on the appliance when the bottle is shut off

Inlet Connection: POL male
Outlet Connection: POL female
Type Of Gas: PROPANE
Total Length: 90mm
Length From Back of POL Connector: 55mm
Total Height: 60mm
Width: 35mm
Nut size 29mm