This is the standard shaft that is shipped with the Mach1GTO from Astro-Physics. It is the same diameter - 1.125" - and uses the same counterweights - 6 lb. (6SLCWT) and 9 lb. (9SLCWT) - as the shafts for their Astro-Physics 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 13.625" and it will hold over 60 lb. of counterweights. The shaft itself weighs in at 4.1 lb. (1.9 kg)
This shaft requires the Machined Safety Stop Knob (MSSKB).
This shaft is recommended for: all 400, 600, 800 and Mach1GTO mounts produced by Astro-Physics. This counterweight shaft can be used on mounts equipped with shaft encoders.
Important Mount Balancing Note: Please click this Pdf link to understand the proper way to position counterweights when balancing your mount.