As discussed on the Home Repair Clinic, below are the charts for Delta faucets. You will find a description, photo and part number for what it is you're looking for. Click on each photo to enlarge. 
 

Delta Parts Sheet Single Handle 


Delta Parts Sheet Stem Units 

 

Delta Parts Tub and Shower Cartridges 
page 1 Single Function


page 2 Dual Function

 

page 3 Single & Dual Function

 

 

 

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