Pocket slider roller

We have a "Pocket Slider" made by Simonton. We need new rollers. After taking it apart, we found it to be a single neoprene wheel with ball bearing in a brass colored casing.

Please note*** This is an older aluminum "Pocket slider" purchased in 2005 but the manufacture date is 97" and is identified as Series 500. Any assistance you might be able to provide us would be greatly appreciated. I look forward to hearing from you.

Thank you,
Kristy