Extang Solid Fold ALX - 17-26 Ridgeline Model 88590Extang Solid Fold ALX 17 26 Ridgeline Model 88590 The Extang Solid Fold 2. 0 is a hard, tri fold truck bed cover. The Solid Fold 2. 0 tonneau is made with TPO dent resistant panels and integrated snap on seals to make the most durable and weather resistant hard folding cover on the market. The Solid Fold 2. 0 has a textured, matte finish that gives the 2. 0 an unmatched OEM look. The Solid Fold 2. 0 comes fully assembled out of the box and installs in