While the glides are overall, the inside dimension is 3/8 and fit a specific track (with a 3/8 rail). Use with Ceiling or Wall Mount Curtain Track A201 or A202. Sew to drapes and use with wall or ceiling track. Glide-tape (#9) 1/2 inch wide. 72 inches per package. Glide-tape (#9) 1/2″. Sew to drapes and use with wall or ceiling track. Glides 72 inches.