Im using these (the one on the right) http://www.brewershardware.com/Valve-and-LPG-Orifice-for-BURN10.html
They are for converting to LP gas at 11" WC.. from the normal HP orifice that comes with a Banjo
(The one on the Left being for Natural Gas an the one on the right is for low pressure LP)
Buying the LP one is saving me the silly drilling process to guess which orifice will work.
They DONT convert high pressure gas to low pressure.. The convert the Burner so it'll run on Low pressure