These blocks are extremely versatile and can be used in several situations. They provide a secure basing for fixings and are good for external and cavity walls. They are fire resistant and feature sound insulation properties. Can also be used for the construction of high strength retaining walls, for external walls, cavity walls, partition walls and party walls. For a solid block with high strength capabilities, use the Solid Dense Concrete Block 7.3N that is also available to buy from us. Hollow Dense 7.3N Concrete Block is only available from us in the one size of 440 x 215 x 215mm. For any further advice or assistance, speak to a member of our team on 01628 249 405. 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.