Husqvarna P524 EFI Workshop Manual page 22

Pull up the PTO button to operate a PTO clutch that
enables the blades to rotate. The blades stop turning
when you push down the PTO button.
The cutting height lever is attached to the shaft with a
joint and a spring. The cutting height lever can be put in
6 operation positions and 1 service position.
22 - Function overview 662 - 001 - 23.10.2018