Radium Transmission Filter, Nissan R35 GT-R, Stainless The Radium transmission filter was designed specifically for the GR6 transmission found in the 2007+ Nissan R35 GT-R. Unlike the OEM filter, the element is made from stainless steel wire mesh and can be cleaned and reused for a lifetime of service. The 40 micron element is also pleated, creating 5 times more surface area for longer service life.