This Part will only work on models that have a two piece Wear Ring / Jet Pump.  
This will replace the Wear Ring Portion. 
However, some models came from the factory with a 1 piece Wear Ring / Jet Pump Assembly.
If you have the one piece model please order part number 513121-2 

This fits all applications.   
If you're wear ring and Jet Pump are two Separate pieces this will replace both pieces. 
However, you can purchase just the Wear Ring / housing by ordering our 513121-2 
513121-2 will only work if you have a 2 piece Wearing / Jet Pump.