- 164mm Stainless Steel Counterweight Shaft It has M12 external threads and M12 internal threads at the bottom (can be connected with M12 threaded extension rods). It is suitable for counterweights with a 2cm aperture and is used for products such as 80EQ, 80DX, Celestron PS and AM series. - 314mm Stainless Steel Counterweight Shaft It has M16 external threads and M12 internal threads at the bottom (can be connected with M12 threaded extension rods). It is suitable for counterweights with a 2cm aperture and is used for equatorial mounts such as SAGTI, XYGTI, HEQ5, EQ6R, EQ3, EXOS - 1, EXOS - 2, AVX and Xinda harmonic equatorial mounts. - 470mm (combined) counterweight shaft is suitable for Xinda W150i - B00/W100i - B00 harmonic and other equatorial mounts