This 4" wide x 8" high x 16" long Regular Concrete Masonry Unit (CMU) is used in load-bearing and non-load-bearing walls and structures. Their standard size makes them easy to work with, and they can be quickly assembled to form a sturdy wall. Concrete blocks provide an insulated, long-lasting structure resistant to fire, moisture, and pest. They are a great choice for a construction project where strength, durability, and affordability are key factors.