nodeko ösi object roller gliders.
These roller gliders will fit many wide channel curtain tracks which already use roller gliders and will be a suitable substitute for many tracks which use standard gliders. Roller gliders will be smoother and more durable than standard gliders and if your track is struggling to cope with heavy curtains using standard gliders, then upgrading to roller gliders should help.
Most hand drawn track use standard gliders and generally corded and electronic curtain tracks use roller gliders.
NOTE sold in quantities of 1, photo for illustration.