bathtub valve identification for seats/springs

Hello,
I have a drip leak in my bathtub. it is a price pfister assembly that can only move counterclockwise to open and clockwise to close. it turns on the water and adjusts the temperature with this motion. probably doesn't need explaining but it gets hotter the farther counterclockwise it is turned.

The seats appear to be dry rotted (attached pic). I went to some big box stores to look for a repair kit but didn't find the exact right ones. So i want to order online but don't know how to identify the part i need.

Does the valve type described above have a name I can reference with price pfister so as to order the correct seats and springs?

thanks!