sliding door part

Hi there, thanks for posting with your sliding door information. This is certainly a great start, but we'll need to see a photo of the roller to make an accurate recommendation. 

Hello,

I believe what you are showing is the internal part of a patio roller. You will need to remove your complete roller from the patio door to identify the one you need. Take a look at the ones suggested to see if yours match up to one of these or any others on the web site. Thank you!