Our FLATHEAD: 10' Octagonal Treehouse Kit includes the specialty hardware to build a perfect octagonal treehouse. The structure is supported to the tree with 2 main supporting bolts and 4 knee braces. This kit supports this plan (sold separately): THE FLATHEAD PLAN This hardware kit will support a platform or house with dimensions up to 10’x10’ octagon (83 square foot) KIT INCLUDES: 2 - TAB 1x9 Bolts w/nuts (Options for Powder Coated and Non-Powder Coated) 2 - 1-1/4" Pipe Brackets 4 - 1-1/4" Single Knee Brace Brackets 4 - 1-1/4" x 8" Galvanized Lag Bolts 8 - 5/8" Carriage Bolts w/flat washers, lock washers, and nuts. Purchasing our hardware in a kit SAVES YOU 5% vs purchasing pieces individually. You're saving $12 purchasing this hardware in a kit! NOTE: - The number of supports on platforms will vary depending on the size of your kit. - Kits exclude plans & Lumber - All plans are non-refundable. -Some photos were customer supplied and may not fully represent the plans.  The renderings will always be an accurate representation of what the plans will include.