The 12-ft x 16-ft Trex Deck Kit includes: 25 Trex Enhance® Naturals 16-ft Grooved Composite Deck Boards; 7 Trex Enhance® Naturals 8-ft Square Composite Deck Boards; 360 Trex Hideaway® Hidden Fasteners and 16 Start Clips; 5 Trex Trim 12-ft White Composite Fascia Deck Boards. The Trex Deck Kit is designed for and includes all materials necessary for a 192-sq. ft. deck build. The Trex Deck Kit does not include a substructure. Composite decks can be built on an existing substructure or materials for one can be purchased separately. Additional non-Trex fasteners may be needed and must be purchased separately.