Gro-Slabs provide the final stage for growing a spectacularly large plant. Transplant your Gro-Block plant onto a slab just like professional growers. They come in clearly marked biodegradable UV resistant sleeves for comfortable handling and algae prevention. Uni-slab - All plant roots are protected and contained for the life of the plant. Due to its size, the Uni-Slab is perfect for one large plant. Uni-Slab has the benefits of a slab with the versatility of a block. Expert slabs have vertical fibers for faster drainage; best for hobbyists. Classic slabs have horizontal fibers for slower drainage; best for hot/dry climates. Vertical fibers in Expert slabs provide faster drainage - best for hobbyists. Horizontal fibers in Classic slabs provide slower drainage - best for hot/dry climates. Sizes available: Expert Fat Slab - 36" x 6" x 4" case of 12 Expert Slab - 36" x 6" x 3" case of 12 Expert Slab - 36" x 8" x 3" case of 12 Classic Slab - 36" x 12" x 3" case of 8 Uni-Slab - 9.5" x 8" x 4" case of 16