This is our superb Platter Damping Ring (PDR), designed to fit tightly around the rim of the platter effectively forming a peripheral wave trap to absorb vibration / resonances / platter 'ring' and enhance rotational stability. This ring is 10mm deep, so it fits most turntables with glass platters perfectly, but it will fit any turntable with a standard diameter platter, providing it is at least 10mm deep. We have sold over 1000 PDR's and the feedback has been amazing, with them working sonic magic on turntables as varied as Thorens, Roksan, Linn, Project, Ariston and Garrard. The PDR is made from a particular type and grade of rubber-like synthetic polymer, specifically selected for its damping properties at the frequencies which cause problems within LP replay systems.