Luomorgo ZXHAO 23mm/0.91 inch Length White Plastic Curtain Track Carrier Glide Rollers 50Pcs

good afternoon! tell me please, is the clip for curtains opens and closes? or is it solid?

Where can i buy the glider track for zxhao 23mm/0.91 inch length white plastic curtain track carrier glide rollers?

Are these meant to be sewn into the curtain then slid into track?

is there a tool to attach?