Lower track

Hello there!

Thanks for contacting us. It's hard to determine if this track is for concave or convex rollers. Can you upload a photo of the roller wheel? That would allow us to confirm. 

Thank you kindly for the additional photo! It's a huge help. I recommend our 23-270, 23-271, or 23-272 bottom track depending on the length that you need. Take a look and let me know if you have any questions.