The original part worn out and so I thought I create a new one. I've started in Fusion 360 but got stuck with the inner sawtooth part, I couldn't get it to the right diameter. So I exported this to Lightwave Modeler and did the scaling there. The four upper parts aren't connected with the main part but Slic3r wasn't complaining about it and created a print model.
I've printed it with 0.1 mm layer height and slightly reduced print speed due to the fine details especially on the inside. It is important to avoid stringing since this will make it hard to match to the metal part of the water tap handle. Some brim may improve stability and no support required.
reduced print speed to increase details especially on the inner part
remove all stringers from the inside