"These are great. We needed to cover some wires and have access to them in the future. These brass cups make it all look very neat and the wood will not rip when we remove the screws for access. I wish we had discovered them years ago and will definitely use them again in the future. You will need a 10mm drill to set them in but do not worry if the edge of the hole is not perfect. The brass will cover the hole edge as you screw in as there is a slight lip on the edge. You can leave the edge proud or pull it into the wood for a flush finish.....A1 product."