Abstract: A machine tool (100) is arranged to deliver at least one of an energy source and a media, through a processing head (300) onto a work-piece for material addition, inspection or data collection, wherein the machine-tool has a clamping mechanism (202) arranged to temporarily receive the processing-head and wherein the machine tool comprises a stop block (390) having a manifold arranged to deliver at least one of the energy and media and wherein the processing head comprises an anti-rotation arm (391) and connector (600) arranged to be connectable to the stop block and wherein the processing head further comprises a manifold arranged to engage with the stop block manifold when the processing head is connected to receive the energy or media. The machine tool may be a multi-axis machine tool and the stop block can be fixed to the machine tool or may be integrated therein.