PRD saftey device
The PRD is a saftey device for a shower and is normally activated if your shower has underlying issues or a burst of water pressure to the unit. see our product page for the 82800450 for reasons of activation.
The ball is not a product supplied by the manufacturer and they dont recommend fitting this part. Once the ball has been activated and forced out of the casing its supplied in, then a new PRD should be fitted. If you choose to fit just a universal rubber ball and its not the correct size then it may not ease out when the pressure gets above the recommended pressure causing more problems for your shower. EG: blown heating can... Remember the PRD is a saftey device for your shower and not fitting manufacturer products can void any warranty on your shower.