CRL's XA TAPER-LOC® Taper Set for 17.52 mm or 21.52 mm laminated glass is made up of two Tapers. Tapers are made of high strength reinforced nylon and aluminum. They expand in thickness when compressed together with the Cat. No. TLK12 Installation/Removal Tool, mechanically locking the glass panel into the base shoe. Not designed for Monolithic glazing. Minimum order is 20 Sets.