There is nothing like a clean tidy sandbox to keep children of all ages safely occupied for hours and hours. The 12"" high Octagonal sandbox is assembled in an hour or so, using the Frame It All joints and four feet long composite plastic timbers, which never rot, splinter and warp or lose their gorgeous natural wood grain finish. Don"t forget to also purchase the heavy duty customiized sandbox cover to keep it clean and dry. Includes:. 4 Raised Garden & Sandbox Kit (SBX-FNP-VAL). 1 Octagon Sandbox Liner. Or. 8 Stacking Joint 2-Packs. 16 Composite Plastic Timbers. 1 Octagon Sandbox Liner. eco-friendly made from recycled plastic. splinter and toxin free. never rots. easy to install. Sand estimates usage: 54 cu ft, 2 cu yards or 5550 lbs