Performance Jet offers an assortment of mixed flow jet drive wear rings that are produced by a number of manufacturers.  The stock Berkeley wear ring is a stainless ring with no shoulder.  Aggressor, A/T, Dominator and Legend use shouldered rings, both in stainless and bronze.  High Tec Performance offers their composite wear ring, and it is marketed as the ULTIMATE WEAR RING.

All of these rings come in various "under sizes" for those applications where the impeller wear ring skirt has been turned down.  The standard ring size as pressed into the suction housing with a ring insulator is 7.250".  Rings come in under sizes from 0.005" to 0.40".  The width of the wear ring is 1.0625" (or 1-1/16") from the shoulder.  The original Aggressor ring was the only ring that is 1" wide, to match their impellers.  Aggressor rings must be used on the older Aggressor impellers.  Aggressor has now upgraded their impellers and wear rings to the standard size of 1.0625".  The ULTIMATE WEAR RING does not use an insulator because it is made of a non-metallic material. This ring does come in under sizes.  Performance Jet also carries the Axial flow wear rings for the Jacuzzi (N/A) YJ and the Kodiak/Hamilton Jets.