75257 In Sink Erator Cover Control Stopper assembly for 75052, 74052, Cover Control and Pro Cover Control Batch Feed Disposals. This is for the Cover Control model series ONLY. This stopper will not fit model 17 or PRO17 batch feed models. This is the MAGNETIC stopper that is used to turn the disposer on and off. Some people think from the photo this part is made with metal and that's just a reflection from the camera. This is a BLACK PLASTIC FACTORY REPLACEMENT PART. FREE SHIPPING TO USA LOWER 48 ONLY.