No holes to dig, no concrete to mix or pour. Great for decks, sheds, platforms and raised walkways. Dynamic, ultra lightweight cellular concrete ? up to 3 times lighter than traditional aggregate concrete (17lbs vs 48lbs). Highly reinforced with a proprietary blend of several different polyolefin fibers offering superior strength to weight properties, durability and quality. Each block weighs approximately 17.64 lbs. Dimensions: 11.42" (290mm) Wide x 7.48" (190mm) High.