Thank you for you question. The T13020 Delta trim kit includes the gray RP46074 valve cartridge assembly. If you have the same gray RP46074 in your existing valve, you can either use your existing cartridge or replace with the new one that comes with the new trim kit. If you installed your faucet before 2006 and have a white, RP19804, valve cartridge, you can still use the T13020 unit, but you will have to either use your existing RP19804 valve cartridge assembly or purchase a new replacement RP19804, if yours is having any issues. Here is a link to this cartridge assembly:
If you do no have either unit, but you still want to use the T13020, you will want to replace the whole valve body to the Delta MultiChoice R10000 rough valve.
Date published: 2018-07-12