A Blue Class B K209 Engineering brick is a perforated brick that combines both high strength and low water absorption. The product is sold in a smooth texture and made from clay. Engineering bricks are specified for their physical characteristics and not their appearance. They have high compressive strength and low water absorption and are classified only by these properties. PLEASE NOTE: The image is for representative purposes only, if unsure please order a sample Due to the Covid-19 pandemic, brick manufacturers have seen a surge in demand which has led to stock shortages and extended lead times. The price set against the product is based on them being in stock and delivered out of selected depots. We will always try to make sure that our customers' orders are fulfilled, but in the event we cannot supply the bricks within our selected network we will offer an alternative solution where possible.