B-68 Coupling Unit Insert 1/4Unf. These solid brass inserts are a push fit into the coupling unit and are in different sizes. 

B-69 Coupling unit insert M6 Thread. These solid brass inserts are a push fit into the coupling unit and are in different sizes. 

B-71 Br Tube 150Mm-Shaft 5/32 M4End

B-72 Br Tube 175Mm-Shaft 5/32 M4End

B-73 Br Tube 200Mm-Shaft 5/32 M4End

B-74 Br Tube 225Mm-Shaft 5/32 M4End

B-76 Br Tube 275Mm-Shaft 5/32 M4End

B-77 Br Tube 300Mm-Shaft 5/32 M4End

B-78 Br Tube 325Mm-Shaft 5/32 M4End