This screw-on stainless steel counterbalance extension shaft is designed to fit the Sky Watcher EQ6 equatorial mounting and allow the balancing of telescopes up to 12" without the addition of excessive counterbalance weight.

The polished shaft is 140mm long and simply screws onto the end of the existing shaft existing shaft making it 140mm longer. The mount does not require dis-assembly and the extension can be easily removed when not required.

The AC687 extension shaft is only suitable for later counterbalance shafts that feature a larger gauge shaft cap female threaded socket and not the older small 6mm size - see lower picture for guidance (sorry the 6mm one simply isn't strong enough to allow a simple extension like the AC687 - see AC686 for a complete replacement shaft solution.)