Corrosion and rot-proof Will not absorb moisture Will support a 20 ton Air Hydraulic Jack Works great with RV's, Trailers, Big Hauling Trailers, Boat Trailers, and many more Will not break under load, mushroom, or warp Great in soft earth or uneven ground Allows Employer to comply with OSHA Regulation 29 CFR 1926.305 "Blocking for a Firm Foundation" .
