98" Clear Poly U-Channel with 1-1/8" Fin for 3/8" Glass Clear Poly Channel has 1-1/8&quot; (29 mm) Fin Ideal for Use With CRL Deluxe Serenity Sliding Door System Suggested Gap: 13/16&quot; (20 mm) Use Monolithic Tempered Glass Clear Poly Channel has 1-1/8&quot; (28.5 mm) Fin