I purchased this online. I made a mistake with the bolt size and it cannot be used in my home. Please refer to the photos for the measurement location of the product. The diameter of the top of the bolt when viewed directly from above is approximately 6mm. Set of 4 wooden risers, 5cm in height. A small anti-slip sheet was also included. I have lost one of the black covers for the bolt part. Thank you! Below is the product description that was provided. [Wooden Risers] These wooden risers have a natural impression and blend well with any interior. [Easy Installation] They use a screw-in installation method to connect furniture with bolts, allowing for setup in under 5 minutes. The fixed legs support the furniture, keep it elevated from the ground to prevent moisture, and make cleaning easier. They are very suitable for replacing the legs of sofas, beds, tables, benches, cabinets, etc.