This is the standard shaft that is shipped with the Mach1GTO. It is the same diameter - 1.125" - and uses the same counterweights - 6 lb. (6SLCWT), 9 lb. (9SLCWT) and 14 lb. (14SLCWT) - as the shafts for the 400 and 600E mounts. The end that attaches to the mount's declination axis was re-designed and incorporates a lead-in to start you out right and a shoulder to stop the shaft firmly against the counterweight shaft adapter without any binding.
The usable length is 13.675" and it will hold over 60 lb. of counterweights. The shaft itself weighs in at 4.1 lb. (1.8 kg)
This shaft is recommended for:
All 400, 600 and Mach1GTO mounts produced. It cannot be used with 800 mounts or any mounts equipped with shaft encoders due to the extended lead-in threads.
Mach2GTO: You may wish to purchase this shaft if you already own the corresponding counterweights or if the supplied counterweight shaft is too heavy for the scope that you are using.
Important Mount Balancing Note:
Please click this PDF link to understand the proper way to position counterweights when balancing your mount.
Please note that the photo below depicts the -A version and the extended lead-in is not shown.