The 9.
Solutions 5/8"" Rod Connectors is a set of 2 stainless steel connectors suitable for the 5/8"" rods from 9.
Solutions.
This allows you to make your rods longer than they are standard.
You can also place 3/8"" rods perpendicular to 5/8"" rods through the 3/8"" screw hole in the centre or attach a rod to any 3/8"" connection.
The rods themselves have a recess at the end suitable for a 13mm (open-end) wrench with which you can tighten the whole thing.