The "ULTIMATE WEAR RING" is the finest wear ring available today. This ring eliminates the need for an insulator.  It is made up of a rare poly material resulting in a reduction of both the friction and cohesion levels over metal wear rings.
The reduced friction increases hole shot by reducing the horsepower requirement. 
0.750 rings are available in 7.225 (STD) and undersized down to .060.
Fits all Berkeley, Dominator (ser #14440 and later), American Turbine, Legend, & Aggressor Jet Drives.
U.S. Patent# 5324560