Where are you being this number. My first search from your model number the 966xxxxxxx one shows aBought this mower 2016 and am looking for OEM belt 575 852401 that drives the wheels. Unfortunately, Husqvarna has discontinued this part. After ordering an OEM from four companies' web sites, I received a "discontinued" e-mail on all.
I've had aggravating luck with non-OEM belts advertised as "fits" or "for" or "replacement for" when they don't fit, don't work at all, don't work as well, fly off, fail early, etc. My original belt is still working fine but I want a spare.
If anyone could help me find an OEM, I would be elated but that appears impossible so I am asking advice on how/where to get a non-OEM belt that will really work reliably.
Any advice will be appreciated.
539120806 for hydro belt
that is readily available.