There should be an assembly manual. Or at least pipes marked with colored stripes showing how they fit together according to the colors in the picture.
Everything fine, the coasters really stick to the table, don’t slip, and look great.
Very inappropriate and non-eco packaging. Each coaster in a separate plastic bag, then grouped by 5 in another bag, so just unwrapping took me half an hour (I bought more) and created a lot of plastic waste.