Thanks for your help, do you know if this fit to the 5726?You would need the conversion kit including the end link which has a tab that fits into the notch of the rubber strap. I bought mine on ali. Be sure to first install the end link to the watch head and then continue with the strap, i.e. do not install the end link to the strap and then try to have the whole thing installed to the watch head.
What dealer did you go through? Those are both so beautifulGRF for the 5320 and HKF for the 5226