Concrete garden benches

This is a set of benches that I bought at Home Depot about 30 years ago. 35 inches wide 17 inches tall and 13 inches from the front to the back. They sat on our front porch that was weather protected, so they have not had hardly any actual sun exposure and weather exposure. They are very good and stable… Many people have sat on them on my front porch. They are made of a substance that is heavy, but not full concrete. I don’t know what to call the material, but they are cool and very useful the picture shows them in my front yard. I am cleaning them and it also shows how you attach them with the sliding attachment that is under the bench. There’s also one flaw in one of the benchs to the right and it’s been there since I bought it. Home Depot gave a good deal because it had that flaw.