2-Level L-Shaped Raised Garden Eco-friendly timbers are made from recycled plastic and natural fibers. No toxic chemicals. Low maintenance - timbers will not rot, warp, splinter or fade. Composite boards are made from 38% post-consumer recycled plastic and 62% sustainable hardwood fibers. One Inch Series composite kits are made from 1 in. thick, rounded profile boards. 5 Year Warranty