This is a bulkhead mounted gas regulator, complete with a test point and manufacturered by GOK Truma.
There are two versions one with an 8mm fitting and one with a 10mm fitting.
Operates at 30mbar and 1.5Kg/hr. 0129467
Truma GOK Bulkhead-Mounted Regulator 10mm
SKU: 0129467
£72.50Price