These knobs are made using a heart mould and concrete. A M5 screw is then set in place with a nut to fix. The hearts themselves measure 3cm x 2.7cm deep. Due to the natural setting of the concrete no two hearts will look the same due to air bubbles etc. These can be painted in any colour or style you like just let me know when ordering in the comments sections or use the drop down bar to select a specific colour from the first picture. They can always be moulded in plain white or grey concrete. Message if you have any questions I always reply as quickly as I can!