Polycarbonate Sign Holder W/ All-Purpose Clamp - Fits Rectangular Or Square Tubing Racks. No Clamps Or Stems Needed. Made Of Clear Unbreakable Polycarbonate. Can Also Mount To Rectangular Hangrail Using Rh2 Faceout So It Faces Forward. Sizes available are 5.5" x 7" and 7" x 11". Case of 24.