Abstract: A fastening device (10) for securing panels (252) to each other, foundations (258) and other surfaces is disclosed including cam elements (50) which are rotated to fasten with locking plates (29). Specifically, elongated hollow channels (11) are provided of an identical construction including slots (24) formed in the free edges of lips (21, 23) defining a slit opening (19). Grooves (22) are formed in the abutting, outside surfaces of the lips (21, 23) for receipt of seals (214). The heads (216) of the seals (214) in an uncompressed condition are of a height substantially greater than and of a width substantially less than the depth and width of a trough (208) of the groove (22) and are compressible to fit completely within the trough (208). The cam elements (50) are rotatably mounted between the support walls (202) of a U-shaped carrier (200). The upper ends of the support walls (202) integrally terminate in shelves (206) having edges which are slideably mounted in the slots (24) of the channels (11).