This is a tandem roller. I didn't happen to review names or numbers when I had the door off the track. This is my Mom's door on her house built in 1997.
Thanks,
Eli
Tom from SWISCO responded:
November 2, 2016
Thank you for reaching out to us. Your tandem roller looks like our product 81-156. Please compare our product to your current part. We also carry this product in stainless steel. See our product 81-156SS for that option.