These are the brass unions that screw into the front bevel gear chamber of the SOHC cambox and feed oil to the valve guides, via the small bore copper pipes.
The unions are just as per originals (originals were used as patterns), and this means they are 'sided' with the inlet union having a smaller bore than the exhaust union.
The copper pipe is supplied soldered into the nipples (and the nipples only bored after this operation is completed, and full bore checked for throughput - as this soldering process often blocks pipe) and is also slightly longer than required, so it can be gently bent and cut to length to suit the engine. They are sold as a complete set per valve, therefore two (2) sets are required per engine. This item is for an Exhaust Valve Guide set